<?xml version="1.0" encoding="US-ASCII"?>
<!--XBRL Document Created with Wdesk from Workiva-->
<!-- -->
<linkbase xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd" xmlns="http://www.xbrl.org/2003/linkbase" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
  <roleRef roleURI="http://www.qualys.com/role/CommitmentsAndContingencies" xlink:href="qlys-20151231.xsd#CommitmentsAndContingencies" xlink:type="simple" />
  <roleRef roleURI="http://www.qualys.com/role/CommitmentsAndContingenciesAdditionalInformationDetails" xlink:href="qlys-20151231.xsd#CommitmentsAndContingenciesAdditionalInformationDetails" xlink:type="simple" />
  <roleRef roleURI="http://www.qualys.com/role/CommitmentsAndContingenciesFutureMinimumLeasePaymentsDetails" xlink:href="qlys-20151231.xsd#CommitmentsAndContingenciesFutureMinimumLeasePaymentsDetails" xlink:type="simple" />
  <roleRef roleURI="http://www.qualys.com/role/CommitmentsAndContingenciesTables" xlink:href="qlys-20151231.xsd#CommitmentsAndContingenciesTables" xlink:type="simple" />
  <roleRef roleURI="http://www.qualys.com/role/CompanyAndSummaryOfSignificantAccountingPolicies" xlink:href="qlys-20151231.xsd#CompanyAndSummaryOfSignificantAccountingPolicies" xlink:type="simple" />
  <roleRef roleURI="http://www.qualys.com/role/CompanyAndSummaryOfSignificantAccountingPoliciesDetails" xlink:href="qlys-20151231.xsd#CompanyAndSummaryOfSignificantAccountingPoliciesDetails" xlink:type="simple" />
  <roleRef roleURI="http://www.qualys.com/role/CompanyAndSummaryOfSignificantAccountingPoliciesPolicies" xlink:href="qlys-20151231.xsd#CompanyAndSummaryOfSignificantAccountingPoliciesPolicies" xlink:type="simple" />
  <roleRef roleURI="http://www.qualys.com/role/ConsolidatedBalanceSheets" xlink:href="qlys-20151231.xsd#ConsolidatedBalanceSheets" xlink:type="simple" />
  <roleRef roleURI="http://www.qualys.com/role/ConsolidatedBalanceSheetsParenthetical" xlink:href="qlys-20151231.xsd#ConsolidatedBalanceSheetsParenthetical" xlink:type="simple" />
  <roleRef roleURI="http://www.qualys.com/role/ConsolidatedStatementsOfCashFlows" xlink:href="qlys-20151231.xsd#ConsolidatedStatementsOfCashFlows" xlink:type="simple" />
  <roleRef roleURI="http://www.qualys.com/role/ConsolidatedStatementsOfComprehensiveIncome" xlink:href="qlys-20151231.xsd#ConsolidatedStatementsOfComprehensiveIncome" xlink:type="simple" />
  <roleRef roleURI="http://www.qualys.com/role/ConsolidatedStatementsOfIncome" xlink:href="qlys-20151231.xsd#ConsolidatedStatementsOfIncome" xlink:type="simple" />
  <roleRef roleURI="http://www.qualys.com/role/ConsolidatedStatementsOfStockholdersEquity" xlink:href="qlys-20151231.xsd#ConsolidatedStatementsOfStockholdersEquity" xlink:type="simple" />
  <roleRef roleURI="http://www.qualys.com/role/DocumentAndEntityInformation" xlink:href="qlys-20151231.xsd#DocumentAndEntityInformation" xlink:type="simple" />
  <roleRef roleURI="http://www.qualys.com/role/EmployeeStockAndBenefitPlans" xlink:href="qlys-20151231.xsd#EmployeeStockAndBenefitPlans" xlink:type="simple" />
  <roleRef roleURI="http://www.qualys.com/role/EmployeeStockAndBenefitPlansExpenseDetails" xlink:href="qlys-20151231.xsd#EmployeeStockAndBenefitPlansExpenseDetails" xlink:type="simple" />
  <roleRef roleURI="http://www.qualys.com/role/EmployeeStockAndBenefitPlansFairValueAssumptionsStockOptionsDetails" xlink:href="qlys-20151231.xsd#EmployeeStockAndBenefitPlansFairValueAssumptionsStockOptionsDetails" xlink:type="simple" />
  <roleRef roleURI="http://www.qualys.com/role/EmployeeStockAndBenefitPlansOptionsOutstandingAndVestedDetails" xlink:href="qlys-20151231.xsd#EmployeeStockAndBenefitPlansOptionsOutstandingAndVestedDetails" xlink:type="simple" />
  <roleRef roleURI="http://www.qualys.com/role/EmployeeStockAndBenefitPlansPlanInformationDetails" xlink:href="qlys-20151231.xsd#EmployeeStockAndBenefitPlansPlanInformationDetails" xlink:type="simple" />
  <roleRef roleURI="http://www.qualys.com/role/EmployeeStockAndBenefitPlansRestrictedStockDetails" xlink:href="qlys-20151231.xsd#EmployeeStockAndBenefitPlansRestrictedStockDetails" xlink:type="simple" />
  <roleRef roleURI="http://www.qualys.com/role/EmployeeStockAndBenefitPlansStockOptionActivityDetails" xlink:href="qlys-20151231.xsd#EmployeeStockAndBenefitPlansStockOptionActivityDetails" xlink:type="simple" />
  <roleRef roleURI="http://www.qualys.com/role/EmployeeStockAndBenefitPlansTables" xlink:href="qlys-20151231.xsd#EmployeeStockAndBenefitPlansTables" xlink:type="simple" />
  <roleRef roleURI="http://www.qualys.com/role/FairValueOfFinancialInstruments" xlink:href="qlys-20151231.xsd#FairValueOfFinancialInstruments" xlink:type="simple" />
  <roleRef roleURI="http://www.qualys.com/role/FairValueOfFinancialInstrumentsCashAndCashEquivalentsAvailableForSaleSecuritiesRestrictedCashReconciliationDetails" xlink:href="qlys-20151231.xsd#FairValueOfFinancialInstrumentsCashAndCashEquivalentsAvailableForSaleSecuritiesRestrictedCashReconciliationDetails" xlink:type="simple" />
  <roleRef roleURI="http://www.qualys.com/role/FairValueOfFinancialInstrumentsContractualMaturityDetails" xlink:href="qlys-20151231.xsd#FairValueOfFinancialInstrumentsContractualMaturityDetails" xlink:type="simple" />
  <roleRef roleURI="http://www.qualys.com/role/FairValueOfFinancialInstrumentsFairValueHierarchyDetails" xlink:href="qlys-20151231.xsd#FairValueOfFinancialInstrumentsFairValueHierarchyDetails" xlink:type="simple" />
  <roleRef roleURI="http://www.qualys.com/role/FairValueOfFinancialInstrumentsNarrativeDetails" xlink:href="qlys-20151231.xsd#FairValueOfFinancialInstrumentsNarrativeDetails" xlink:type="simple" />
  <roleRef roleURI="http://www.qualys.com/role/FairValueOfFinancialInstrumentsTables" xlink:href="qlys-20151231.xsd#FairValueOfFinancialInstrumentsTables" xlink:type="simple" />
  <roleRef roleURI="http://www.qualys.com/role/GoodwillAndIntangibleAssetsNet" xlink:href="qlys-20151231.xsd#GoodwillAndIntangibleAssetsNet" xlink:type="simple" />
  <roleRef roleURI="http://www.qualys.com/role/GoodwillAndIntangibleAssetsNetDetails" xlink:href="qlys-20151231.xsd#GoodwillAndIntangibleAssetsNetDetails" xlink:type="simple" />
  <roleRef roleURI="http://www.qualys.com/role/GoodwillAndIntangibleAssetsNetFutureAmortizationDetails" xlink:href="qlys-20151231.xsd#GoodwillAndIntangibleAssetsNetFutureAmortizationDetails" xlink:type="simple" />
  <roleRef roleURI="http://www.qualys.com/role/GoodwillAndIntangibleAssetsNetTables" xlink:href="qlys-20151231.xsd#GoodwillAndIntangibleAssetsNetTables" xlink:type="simple" />
  <roleRef roleURI="http://www.qualys.com/role/IncomeTaxes" xlink:href="qlys-20151231.xsd#IncomeTaxes" xlink:type="simple" />
  <roleRef roleURI="http://www.qualys.com/role/IncomeTaxesDeferredTaxAssetsAndLiabilitiesDetails" xlink:href="qlys-20151231.xsd#IncomeTaxesDeferredTaxAssetsAndLiabilitiesDetails" xlink:type="simple" />
  <roleRef roleURI="http://www.qualys.com/role/IncomeTaxesIncomeBeforeProvisionForBenefitFromIncomeTaxesDetails" xlink:href="qlys-20151231.xsd#IncomeTaxesIncomeBeforeProvisionForBenefitFromIncomeTaxesDetails" xlink:type="simple" />
  <roleRef roleURI="http://www.qualys.com/role/IncomeTaxesNarrativeDetails" xlink:href="qlys-20151231.xsd#IncomeTaxesNarrativeDetails" xlink:type="simple" />
  <roleRef roleURI="http://www.qualys.com/role/IncomeTaxesProvisionForBenefitFromIncomeTaxesDetails" xlink:href="qlys-20151231.xsd#IncomeTaxesProvisionForBenefitFromIncomeTaxesDetails" xlink:type="simple" />
  <roleRef roleURI="http://www.qualys.com/role/IncomeTaxesTables" xlink:href="qlys-20151231.xsd#IncomeTaxesTables" xlink:type="simple" />
  <roleRef roleURI="http://www.qualys.com/role/IncomeTaxesTaxRateReconciliationDetails" xlink:href="qlys-20151231.xsd#IncomeTaxesTaxRateReconciliationDetails" xlink:type="simple" />
  <roleRef roleURI="http://www.qualys.com/role/IncomeTaxesUnrecognizedTaxBenefitsDetails" xlink:href="qlys-20151231.xsd#IncomeTaxesUnrecognizedTaxBenefitsDetails" xlink:type="simple" />
  <roleRef roleURI="http://www.qualys.com/role/NetIncomePerShareAttributableToCommonStockholders" xlink:href="qlys-20151231.xsd#NetIncomePerShareAttributableToCommonStockholders" xlink:type="simple" />
  <roleRef roleURI="http://www.qualys.com/role/NetIncomePerShareAttributableToCommonStockholdersDetails" xlink:href="qlys-20151231.xsd#NetIncomePerShareAttributableToCommonStockholdersDetails" xlink:type="simple" />
  <roleRef roleURI="http://www.qualys.com/role/NetIncomePerShareAttributableToCommonStockholdersTables" xlink:href="qlys-20151231.xsd#NetIncomePerShareAttributableToCommonStockholdersTables" xlink:type="simple" />
  <roleRef roleURI="http://www.qualys.com/role/OtherIncomeExpenseNet" xlink:href="qlys-20151231.xsd#OtherIncomeExpenseNet" xlink:type="simple" />
  <roleRef roleURI="http://www.qualys.com/role/OtherIncomeExpenseNetDetails" xlink:href="qlys-20151231.xsd#OtherIncomeExpenseNetDetails" xlink:type="simple" />
  <roleRef roleURI="http://www.qualys.com/role/OtherIncomeExpenseNetTables" xlink:href="qlys-20151231.xsd#OtherIncomeExpenseNetTables" xlink:type="simple" />
  <roleRef roleURI="http://www.qualys.com/role/PropertyAndEquipmentNet" xlink:href="qlys-20151231.xsd#PropertyAndEquipmentNet" xlink:type="simple" />
  <roleRef roleURI="http://www.qualys.com/role/PropertyAndEquipmentNetDetails" xlink:href="qlys-20151231.xsd#PropertyAndEquipmentNetDetails" xlink:type="simple" />
  <roleRef roleURI="http://www.qualys.com/role/PropertyAndEquipmentNetTables" xlink:href="qlys-20151231.xsd#PropertyAndEquipmentNetTables" xlink:type="simple" />
  <roleRef roleURI="http://www.qualys.com/role/QuarterlyFinancialInformationUnaudited" xlink:href="qlys-20151231.xsd#QuarterlyFinancialInformationUnaudited" xlink:type="simple" />
  <roleRef roleURI="http://www.qualys.com/role/QuarterlyFinancialInformationUnauditedDetails" xlink:href="qlys-20151231.xsd#QuarterlyFinancialInformationUnauditedDetails" xlink:type="simple" />
  <roleRef roleURI="http://www.qualys.com/role/QuarterlyFinancialInformationUnauditedTables" xlink:href="qlys-20151231.xsd#QuarterlyFinancialInformationUnauditedTables" xlink:type="simple" />
  <roleRef roleURI="http://www.qualys.com/role/ScheduleIiScheduleOfValuationAndQualifyingAccounts" xlink:href="qlys-20151231.xsd#ScheduleIiScheduleOfValuationAndQualifyingAccounts" xlink:type="simple" />
  <roleRef roleURI="http://www.qualys.com/role/ScheduleIiScheduleOfValuationAndQualifyingAccountsDetails" xlink:href="qlys-20151231.xsd#ScheduleIiScheduleOfValuationAndQualifyingAccountsDetails" xlink:type="simple" />
  <roleRef roleURI="http://www.qualys.com/role/SegmentInformationAndInformationAboutGeographicArea" xlink:href="qlys-20151231.xsd#SegmentInformationAndInformationAboutGeographicArea" xlink:type="simple" />
  <roleRef roleURI="http://www.qualys.com/role/SegmentInformationAndInformationAboutGeographicAreaDetails" xlink:href="qlys-20151231.xsd#SegmentInformationAndInformationAboutGeographicAreaDetails" xlink:type="simple" />
  <roleRef roleURI="http://www.qualys.com/role/SegmentInformationAndInformationAboutGeographicAreaTables" xlink:href="qlys-20151231.xsd#SegmentInformationAndInformationAboutGeographicAreaTables" xlink:type="simple" />
  <roleRef roleURI="http://www.qualys.com/role/StockholdersEquity" xlink:href="qlys-20151231.xsd#StockholdersEquity" xlink:type="simple" />
  <roleRef roleURI="http://www.qualys.com/role/StockholdersEquityDetails" xlink:href="qlys-20151231.xsd#StockholdersEquityDetails" xlink:type="simple" />
  <roleRef roleURI="http://www.qualys.com/role/StockholdersEquityTables" xlink:href="qlys-20151231.xsd#StockholdersEquityTables" xlink:type="simple" />
  <calculationLink xlink:role="http://www.qualys.com/role/CommitmentsAndContingencies" xlink:type="extended" />
  <calculationLink xlink:role="http://www.qualys.com/role/CommitmentsAndContingenciesAdditionalInformationDetails" xlink:type="extended" />
  <calculationLink xlink:role="http://www.qualys.com/role/CommitmentsAndContingenciesFutureMinimumLeasePaymentsDetails" xlink:type="extended">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_OperatingLeasesFutureMinimumPaymentsDue" xlink:label="loc_us-gaap_OperatingLeasesFutureMinimumPaymentsDue_6282e4c0-b0bd-9c84-bf43-857ac02b98fc" xlink:type="locator" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_OperatingLeasesFutureMinimumPaymentsDueCurrent" xlink:label="loc_us-gaap_OperatingLeasesFutureMinimumPaymentsDueCurrent_8a0692b4-cb50-1eeb-12b4-1509099841b7" xlink:type="locator" />
    <calculationArc order="1" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_OperatingLeasesFutureMinimumPaymentsDue_6282e4c0-b0bd-9c84-bf43-857ac02b98fc" xlink:to="loc_us-gaap_OperatingLeasesFutureMinimumPaymentsDueCurrent_8a0692b4-cb50-1eeb-12b4-1509099841b7" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_OperatingLeasesFutureMinimumPaymentsDueInTwoYears" xlink:label="loc_us-gaap_OperatingLeasesFutureMinimumPaymentsDueInTwoYears_4c8190eb-f692-81f2-35bc-182f11d12444" xlink:type="locator" />
    <calculationArc order="2" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_OperatingLeasesFutureMinimumPaymentsDue_6282e4c0-b0bd-9c84-bf43-857ac02b98fc" xlink:to="loc_us-gaap_OperatingLeasesFutureMinimumPaymentsDueInTwoYears_4c8190eb-f692-81f2-35bc-182f11d12444" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_OperatingLeasesFutureMinimumPaymentsDueInThreeYears" xlink:label="loc_us-gaap_OperatingLeasesFutureMinimumPaymentsDueInThreeYears_baee32aa-bbe2-ead3-1f78-a80f542a97a2" xlink:type="locator" />
    <calculationArc order="3" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_OperatingLeasesFutureMinimumPaymentsDue_6282e4c0-b0bd-9c84-bf43-857ac02b98fc" xlink:to="loc_us-gaap_OperatingLeasesFutureMinimumPaymentsDueInThreeYears_baee32aa-bbe2-ead3-1f78-a80f542a97a2" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_OperatingLeasesFutureMinimumPaymentsDueInFourYears" xlink:label="loc_us-gaap_OperatingLeasesFutureMinimumPaymentsDueInFourYears_5e342c11-473b-4170-d672-935adcfdb463" xlink:type="locator" />
    <calculationArc order="4" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_OperatingLeasesFutureMinimumPaymentsDue_6282e4c0-b0bd-9c84-bf43-857ac02b98fc" xlink:to="loc_us-gaap_OperatingLeasesFutureMinimumPaymentsDueInFourYears_5e342c11-473b-4170-d672-935adcfdb463" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_OperatingLeasesFutureMinimumPaymentsDueInFiveYears" xlink:label="loc_us-gaap_OperatingLeasesFutureMinimumPaymentsDueInFiveYears_c48f63ae-e409-59ce-5794-cc7ae6139c21" xlink:type="locator" />
    <calculationArc order="5" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_OperatingLeasesFutureMinimumPaymentsDue_6282e4c0-b0bd-9c84-bf43-857ac02b98fc" xlink:to="loc_us-gaap_OperatingLeasesFutureMinimumPaymentsDueInFiveYears_c48f63ae-e409-59ce-5794-cc7ae6139c21" xlink:type="arc" />
  </calculationLink>
  <calculationLink xlink:role="http://www.qualys.com/role/CommitmentsAndContingenciesTables" xlink:type="extended" />
  <calculationLink xlink:role="http://www.qualys.com/role/CompanyAndSummaryOfSignificantAccountingPolicies" xlink:type="extended" />
  <calculationLink xlink:role="http://www.qualys.com/role/CompanyAndSummaryOfSignificantAccountingPoliciesDetails" xlink:type="extended" />
  <calculationLink xlink:role="http://www.qualys.com/role/CompanyAndSummaryOfSignificantAccountingPoliciesPolicies" xlink:type="extended" />
  <calculationLink xlink:role="http://www.qualys.com/role/ConsolidatedBalanceSheets" xlink:type="extended">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_Assets" xlink:label="loc_us-gaap_Assets_effc14df-fd72-eec8-ede9-64e0071b91bc" xlink:type="locator" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_AssetsCurrent" xlink:label="loc_us-gaap_AssetsCurrent_39eaeb62-7ee3-5503-48f5-08c2dff05e50" xlink:type="locator" />
    <calculationArc order="1" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_effc14df-fd72-eec8-ede9-64e0071b91bc" xlink:to="loc_us-gaap_AssetsCurrent_39eaeb62-7ee3-5503-48f5-08c2dff05e50" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:label="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_cd34decb-53b6-e0a9-28d5-0a9741c4b0f8" xlink:type="locator" />
    <calculationArc order="1" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_AssetsCurrent_39eaeb62-7ee3-5503-48f5-08c2dff05e50" xlink:to="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_cd34decb-53b6-e0a9-28d5-0a9741c4b0f8" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_ShortTermInvestments" xlink:label="loc_us-gaap_ShortTermInvestments_777309da-a5d9-d5ab-d632-48c8a96679c2" xlink:type="locator" />
    <calculationArc order="2" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_AssetsCurrent_39eaeb62-7ee3-5503-48f5-08c2dff05e50" xlink:to="loc_us-gaap_ShortTermInvestments_777309da-a5d9-d5ab-d632-48c8a96679c2" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_AccountsReceivableNetCurrent" xlink:label="loc_us-gaap_AccountsReceivableNetCurrent_4d24e56f-a5cb-07ba-0508-f5f1533ae24e" xlink:type="locator" />
    <calculationArc order="3" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_AssetsCurrent_39eaeb62-7ee3-5503-48f5-08c2dff05e50" xlink:to="loc_us-gaap_AccountsReceivableNetCurrent_4d24e56f-a5cb-07ba-0508-f5f1533ae24e" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_PrepaidExpenseAndOtherAssetsCurrent" xlink:label="loc_us-gaap_PrepaidExpenseAndOtherAssetsCurrent_f186537c-a0b4-9ca7-f59a-958a18f111e6" xlink:type="locator" />
    <calculationArc order="4" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_AssetsCurrent_39eaeb62-7ee3-5503-48f5-08c2dff05e50" xlink:to="loc_us-gaap_PrepaidExpenseAndOtherAssetsCurrent_f186537c-a0b4-9ca7-f59a-958a18f111e6" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_LongTermInvestments" xlink:label="loc_us-gaap_LongTermInvestments_27d14e42-ada3-42c7-e1aa-70cd856fa1fe" xlink:type="locator" />
    <calculationArc order="2" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_effc14df-fd72-eec8-ede9-64e0071b91bc" xlink:to="loc_us-gaap_LongTermInvestments_27d14e42-ada3-42c7-e1aa-70cd856fa1fe" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_PropertyPlantAndEquipmentNet" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentNet_7ce178a4-245f-fa78-36a1-552609a67554" xlink:type="locator" />
    <calculationArc order="3" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_effc14df-fd72-eec8-ede9-64e0071b91bc" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentNet_7ce178a4-245f-fa78-36a1-552609a67554" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_IntangibleAssetsNetExcludingGoodwill" xlink:label="loc_us-gaap_IntangibleAssetsNetExcludingGoodwill_894a128f-2068-d267-1e3e-64c93d0ed5ca" xlink:type="locator" />
    <calculationArc order="4" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_effc14df-fd72-eec8-ede9-64e0071b91bc" xlink:to="loc_us-gaap_IntangibleAssetsNetExcludingGoodwill_894a128f-2068-d267-1e3e-64c93d0ed5ca" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_Goodwill" xlink:label="loc_us-gaap_Goodwill_b108d604-1348-4e65-3817-2944b734c65a" xlink:type="locator" />
    <calculationArc order="5" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_effc14df-fd72-eec8-ede9-64e0071b91bc" xlink:to="loc_us-gaap_Goodwill_b108d604-1348-4e65-3817-2944b734c65a" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_OtherAssetsNoncurrent" xlink:label="loc_us-gaap_OtherAssetsNoncurrent_9b98e689-e6db-3e5b-e5c3-3324fffb4edf" xlink:type="locator" />
    <calculationArc order="6" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_effc14df-fd72-eec8-ede9-64e0071b91bc" xlink:to="loc_us-gaap_OtherAssetsNoncurrent_9b98e689-e6db-3e5b-e5c3-3324fffb4edf" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_DeferredTaxAssetsLiabilitiesNetNoncurrent" xlink:label="loc_us-gaap_DeferredTaxAssetsLiabilitiesNetNoncurrent_d4c273a2-489c-2eba-2ea8-121e3528a113" xlink:type="locator" />
    <calculationArc order="7" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_effc14df-fd72-eec8-ede9-64e0071b91bc" xlink:to="loc_us-gaap_DeferredTaxAssetsLiabilitiesNetNoncurrent_d4c273a2-489c-2eba-2ea8-121e3528a113" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_LiabilitiesAndStockholdersEquity" xlink:label="loc_us-gaap_LiabilitiesAndStockholdersEquity_4a314f0d-c6fa-5cf2-0be1-add747465af3" xlink:type="locator" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_Liabilities" xlink:label="loc_us-gaap_Liabilities_4e70462c-e5f6-e2d9-0cf5-7f1332ddbc05" xlink:type="locator" />
    <calculationArc order="1" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquity_4a314f0d-c6fa-5cf2-0be1-add747465af3" xlink:to="loc_us-gaap_Liabilities_4e70462c-e5f6-e2d9-0cf5-7f1332ddbc05" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_LiabilitiesCurrent" xlink:label="loc_us-gaap_LiabilitiesCurrent_1de50dbc-01a9-6657-f83f-d1e74edfdf18" xlink:type="locator" />
    <calculationArc order="1" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Liabilities_4e70462c-e5f6-e2d9-0cf5-7f1332ddbc05" xlink:to="loc_us-gaap_LiabilitiesCurrent_1de50dbc-01a9-6657-f83f-d1e74edfdf18" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_AccountsPayableCurrent" xlink:label="loc_us-gaap_AccountsPayableCurrent_22caddf9-3843-6329-6e39-dc458323b572" xlink:type="locator" />
    <calculationArc order="1" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesCurrent_1de50dbc-01a9-6657-f83f-d1e74edfdf18" xlink:to="loc_us-gaap_AccountsPayableCurrent_22caddf9-3843-6329-6e39-dc458323b572" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_AccruedLiabilitiesCurrent" xlink:label="loc_us-gaap_AccruedLiabilitiesCurrent_eaf92fb1-642d-2c65-5ba7-1a63a3697f47" xlink:type="locator" />
    <calculationArc order="2" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesCurrent_1de50dbc-01a9-6657-f83f-d1e74edfdf18" xlink:to="loc_us-gaap_AccruedLiabilitiesCurrent_eaf92fb1-642d-2c65-5ba7-1a63a3697f47" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_DeferredRevenueCurrent" xlink:label="loc_us-gaap_DeferredRevenueCurrent_a33614ee-2047-2d07-d4dc-cd97b29aa0eb" xlink:type="locator" />
    <calculationArc order="3" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesCurrent_1de50dbc-01a9-6657-f83f-d1e74edfdf18" xlink:to="loc_us-gaap_DeferredRevenueCurrent_a33614ee-2047-2d07-d4dc-cd97b29aa0eb" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_DeferredRevenueNoncurrent" xlink:label="loc_us-gaap_DeferredRevenueNoncurrent_4ca8aac1-2306-11d6-0ee3-d0bcb454b02f" xlink:type="locator" />
    <calculationArc order="2" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Liabilities_4e70462c-e5f6-e2d9-0cf5-7f1332ddbc05" xlink:to="loc_us-gaap_DeferredRevenueNoncurrent_4ca8aac1-2306-11d6-0ee3-d0bcb454b02f" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_OtherLiabilitiesNoncurrent" xlink:label="loc_us-gaap_OtherLiabilitiesNoncurrent_7f5c7cfd-4659-429c-35ab-266d67961421" xlink:type="locator" />
    <calculationArc order="3" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Liabilities_4e70462c-e5f6-e2d9-0cf5-7f1332ddbc05" xlink:to="loc_us-gaap_OtherLiabilitiesNoncurrent_7f5c7cfd-4659-429c-35ab-266d67961421" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_StockholdersEquity" xlink:label="loc_us-gaap_StockholdersEquity_d0f349aa-18e3-6323-86ad-665f8773c064" xlink:type="locator" />
    <calculationArc order="2" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquity_4a314f0d-c6fa-5cf2-0be1-add747465af3" xlink:to="loc_us-gaap_StockholdersEquity_d0f349aa-18e3-6323-86ad-665f8773c064" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_PreferredStockValue" xlink:label="loc_us-gaap_PreferredStockValue_359b0ac4-80ce-a291-f73b-cff103b81eae" xlink:type="locator" />
    <calculationArc order="1" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquity_d0f349aa-18e3-6323-86ad-665f8773c064" xlink:to="loc_us-gaap_PreferredStockValue_359b0ac4-80ce-a291-f73b-cff103b81eae" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_CommonStockValue" xlink:label="loc_us-gaap_CommonStockValue_ce40a301-9b6b-9fc3-bfb6-dfbb8fcdf29b" xlink:type="locator" />
    <calculationArc order="2" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquity_d0f349aa-18e3-6323-86ad-665f8773c064" xlink:to="loc_us-gaap_CommonStockValue_ce40a301-9b6b-9fc3-bfb6-dfbb8fcdf29b" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_AdditionalPaidInCapital" xlink:label="loc_us-gaap_AdditionalPaidInCapital_9158c8ad-1189-2464-9c41-553e6a22df6c" xlink:type="locator" />
    <calculationArc order="3" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquity_d0f349aa-18e3-6323-86ad-665f8773c064" xlink:to="loc_us-gaap_AdditionalPaidInCapital_9158c8ad-1189-2464-9c41-553e6a22df6c" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_dd6b7206-c19f-4dd5-339b-1369c57cfe0f" xlink:type="locator" />
    <calculationArc order="4" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquity_d0f349aa-18e3-6323-86ad-665f8773c064" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_dd6b7206-c19f-4dd5-339b-1369c57cfe0f" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_RetainedEarningsAccumulatedDeficit" xlink:label="loc_us-gaap_RetainedEarningsAccumulatedDeficit_1d565cd0-d7bf-de89-4dbe-a484007b1fe8" xlink:type="locator" />
    <calculationArc order="5" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquity_d0f349aa-18e3-6323-86ad-665f8773c064" xlink:to="loc_us-gaap_RetainedEarningsAccumulatedDeficit_1d565cd0-d7bf-de89-4dbe-a484007b1fe8" xlink:type="arc" />
  </calculationLink>
  <calculationLink xlink:role="http://www.qualys.com/role/ConsolidatedBalanceSheetsParenthetical" xlink:type="extended" />
  <calculationLink xlink:role="http://www.qualys.com/role/ConsolidatedStatementsOfCashFlows" xlink:type="extended">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease" xlink:label="loc_us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease_ff5db18e-7b91-5a5d-e914-0527b02a8012" xlink:type="locator" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:label="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_916e1eb7-21fa-e5f0-a15f-0b05ed633776" xlink:type="locator" />
    <calculationArc order="1" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease_ff5db18e-7b91-5a5d-e914-0527b02a8012" xlink:to="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_916e1eb7-21fa-e5f0-a15f-0b05ed633776" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_NetIncomeLoss" xlink:label="loc_us-gaap_NetIncomeLoss_e62ce8b8-4401-2622-8598-3e644745e95e" xlink:type="locator" />
    <calculationArc order="1" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_916e1eb7-21fa-e5f0-a15f-0b05ed633776" xlink:to="loc_us-gaap_NetIncomeLoss_e62ce8b8-4401-2622-8598-3e644745e95e" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_DepreciationDepletionAndAmortization" xlink:label="loc_us-gaap_DepreciationDepletionAndAmortization_783b94c5-664a-4bc7-f813-8c258cc934b7" xlink:type="locator" />
    <calculationArc order="2" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_916e1eb7-21fa-e5f0-a15f-0b05ed633776" xlink:to="loc_us-gaap_DepreciationDepletionAndAmortization_783b94c5-664a-4bc7-f813-8c258cc934b7" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_ProvisionForDoubtfulAccounts" xlink:label="loc_us-gaap_ProvisionForDoubtfulAccounts_030f5c40-af7e-2a00-2417-01509e80b7e6" xlink:type="locator" />
    <calculationArc order="3" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_916e1eb7-21fa-e5f0-a15f-0b05ed633776" xlink:to="loc_us-gaap_ProvisionForDoubtfulAccounts_030f5c40-af7e-2a00-2417-01509e80b7e6" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_GainLossOnSaleOfPropertyPlantEquipment" xlink:label="loc_us-gaap_GainLossOnSaleOfPropertyPlantEquipment_466891d8-a228-268b-1fd8-1eca117e27a6" xlink:type="locator" />
    <calculationArc order="4" weight="-1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_916e1eb7-21fa-e5f0-a15f-0b05ed633776" xlink:to="loc_us-gaap_GainLossOnSaleOfPropertyPlantEquipment_466891d8-a228-268b-1fd8-1eca117e27a6" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_ShareBasedCompensation" xlink:label="loc_us-gaap_ShareBasedCompensation_d4c99b59-c44a-c4ac-309f-0bddfdb944a5" xlink:type="locator" />
    <calculationArc order="5" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_916e1eb7-21fa-e5f0-a15f-0b05ed633776" xlink:to="loc_us-gaap_ShareBasedCompensation_d4c99b59-c44a-c4ac-309f-0bddfdb944a5" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_AccretionAmortizationOfDiscountsAndPremiumsInvestments" xlink:label="loc_us-gaap_AccretionAmortizationOfDiscountsAndPremiumsInvestments_3ef3660d-f952-6ded-6018-37f75b491ea0" xlink:type="locator" />
    <calculationArc order="6" weight="-1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_916e1eb7-21fa-e5f0-a15f-0b05ed633776" xlink:to="loc_us-gaap_AccretionAmortizationOfDiscountsAndPremiumsInvestments_3ef3660d-f952-6ded-6018-37f75b491ea0" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_ExcessTaxBenefitFromShareBasedCompensationOperatingActivities" xlink:label="loc_us-gaap_ExcessTaxBenefitFromShareBasedCompensationOperatingActivities_b841fb4f-3c0e-cd5c-bbc1-86e011a106f2" xlink:type="locator" />
    <calculationArc order="7" weight="-1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_916e1eb7-21fa-e5f0-a15f-0b05ed633776" xlink:to="loc_us-gaap_ExcessTaxBenefitFromShareBasedCompensationOperatingActivities_b841fb4f-3c0e-cd5c-bbc1-86e011a106f2" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_DeferredIncomeTaxesAndTaxCredits" xlink:label="loc_us-gaap_DeferredIncomeTaxesAndTaxCredits_327ab773-698f-0b50-f5d2-8402f0d40141" xlink:type="locator" />
    <calculationArc order="8" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_916e1eb7-21fa-e5f0-a15f-0b05ed633776" xlink:to="loc_us-gaap_DeferredIncomeTaxesAndTaxCredits_327ab773-698f-0b50-f5d2-8402f0d40141" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_IncreaseDecreaseInAccountsReceivable" xlink:label="loc_us-gaap_IncreaseDecreaseInAccountsReceivable_91d80b53-6368-7466-a11d-02030d33de5c" xlink:type="locator" />
    <calculationArc order="9" weight="-1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_916e1eb7-21fa-e5f0-a15f-0b05ed633776" xlink:to="loc_us-gaap_IncreaseDecreaseInAccountsReceivable_91d80b53-6368-7466-a11d-02030d33de5c" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets" xlink:label="loc_us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets_709900d0-f7b0-b950-eae5-eeb8fc36b367" xlink:type="locator" />
    <calculationArc order="10" weight="-1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_916e1eb7-21fa-e5f0-a15f-0b05ed633776" xlink:to="loc_us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets_709900d0-f7b0-b950-eae5-eeb8fc36b367" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_IncreaseDecreaseInAccountsPayable" xlink:label="loc_us-gaap_IncreaseDecreaseInAccountsPayable_a167e25c-e8b1-aeb8-f355-3727e3f06f3e" xlink:type="locator" />
    <calculationArc order="11" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_916e1eb7-21fa-e5f0-a15f-0b05ed633776" xlink:to="loc_us-gaap_IncreaseDecreaseInAccountsPayable_a167e25c-e8b1-aeb8-f355-3727e3f06f3e" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_IncreaseDecreaseInAccruedLiabilities" xlink:label="loc_us-gaap_IncreaseDecreaseInAccruedLiabilities_1ea297cc-8653-7155-6fa9-a3af7df49950" xlink:type="locator" />
    <calculationArc order="12" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_916e1eb7-21fa-e5f0-a15f-0b05ed633776" xlink:to="loc_us-gaap_IncreaseDecreaseInAccruedLiabilities_1ea297cc-8653-7155-6fa9-a3af7df49950" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_IncreaseDecreaseInDeferredRevenue" xlink:label="loc_us-gaap_IncreaseDecreaseInDeferredRevenue_ccf69244-7aaf-19cf-90d6-269f163732c4" xlink:type="locator" />
    <calculationArc order="13" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_916e1eb7-21fa-e5f0-a15f-0b05ed633776" xlink:to="loc_us-gaap_IncreaseDecreaseInDeferredRevenue_ccf69244-7aaf-19cf-90d6-269f163732c4" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_IncreaseDecreaseInOtherNoncurrentLiabilities" xlink:label="loc_us-gaap_IncreaseDecreaseInOtherNoncurrentLiabilities_e998242e-fd71-e5c7-b09b-5694b86255c9" xlink:type="locator" />
    <calculationArc order="14" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_916e1eb7-21fa-e5f0-a15f-0b05ed633776" xlink:to="loc_us-gaap_IncreaseDecreaseInOtherNoncurrentLiabilities_e998242e-fd71-e5c7-b09b-5694b86255c9" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_ImpairmentOfIntangibleAssetsFinitelived" xlink:label="loc_us-gaap_ImpairmentOfIntangibleAssetsFinitelived_616da735-620b-137d-42af-741695b55739" xlink:type="locator" />
    <calculationArc order="15" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_916e1eb7-21fa-e5f0-a15f-0b05ed633776" xlink:to="loc_us-gaap_ImpairmentOfIntangibleAssetsFinitelived_616da735-620b-137d-42af-741695b55739" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivities" xlink:label="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_58a5bd26-e5f4-de8f-6118-f713733148b8" xlink:type="locator" />
    <calculationArc order="2" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease_ff5db18e-7b91-5a5d-e914-0527b02a8012" xlink:to="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_58a5bd26-e5f4-de8f-6118-f713733148b8" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_PaymentsToAcquireAvailableForSaleSecurities" xlink:label="loc_us-gaap_PaymentsToAcquireAvailableForSaleSecurities_11bab1ef-563b-9c08-d855-5223ff2c6591" xlink:type="locator" />
    <calculationArc order="1" weight="-1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_58a5bd26-e5f4-de8f-6118-f713733148b8" xlink:to="loc_us-gaap_PaymentsToAcquireAvailableForSaleSecurities_11bab1ef-563b-9c08-d855-5223ff2c6591" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_ProceedsFromSaleAndMaturityOfAvailableForSaleSecurities" xlink:label="loc_us-gaap_ProceedsFromSaleAndMaturityOfAvailableForSaleSecurities_198988d2-2f05-3f47-d4f0-bce81f98eaf0" xlink:type="locator" />
    <calculationArc order="2" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_58a5bd26-e5f4-de8f-6118-f713733148b8" xlink:to="loc_us-gaap_ProceedsFromSaleAndMaturityOfAvailableForSaleSecurities_198988d2-2f05-3f47-d4f0-bce81f98eaf0" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_PaymentsToAcquirePropertyPlantAndEquipment" xlink:label="loc_us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_386292ff-155c-0309-455a-2b91b395b3da" xlink:type="locator" />
    <calculationArc order="3" weight="-1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_58a5bd26-e5f4-de8f-6118-f713733148b8" xlink:to="loc_us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_386292ff-155c-0309-455a-2b91b395b3da" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_IncreaseDecreaseInRestrictedCash" xlink:label="loc_us-gaap_IncreaseDecreaseInRestrictedCash_8c9d9d5e-0593-ae0e-95c3-bce133b31671" xlink:type="locator" />
    <calculationArc order="4" weight="-1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_58a5bd26-e5f4-de8f-6118-f713733148b8" xlink:to="loc_us-gaap_IncreaseDecreaseInRestrictedCash_8c9d9d5e-0593-ae0e-95c3-bce133b31671" xlink:type="arc" />
    <loc xlink:href="qlys-20151231.xsd#qlys_CapitalizedSoftwareDevelopmentCosts" xlink:label="loc_qlys_CapitalizedSoftwareDevelopmentCosts_E4829FEB02A5B54F7EB6062839439072" xlink:type="locator" />
    <calculationArc order="5" weight="-1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_58a5bd26-e5f4-de8f-6118-f713733148b8" xlink:to="loc_qlys_CapitalizedSoftwareDevelopmentCosts_E4829FEB02A5B54F7EB6062839439072" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivities" xlink:label="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_a678c20d-a481-ef6a-800a-4bd566075d81" xlink:type="locator" />
    <calculationArc order="3" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease_ff5db18e-7b91-5a5d-e914-0527b02a8012" xlink:to="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_a678c20d-a481-ef6a-800a-4bd566075d81" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_ProceedsFromStockOptionsExercised" xlink:label="loc_us-gaap_ProceedsFromStockOptionsExercised_f1b85fa1-97cd-57cc-5318-fb8dd976eb81" xlink:type="locator" />
    <calculationArc order="1" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_a678c20d-a481-ef6a-800a-4bd566075d81" xlink:to="loc_us-gaap_ProceedsFromStockOptionsExercised_f1b85fa1-97cd-57cc-5318-fb8dd976eb81" xlink:type="arc" />
    <loc xlink:href="qlys-20151231.xsd#qlys_ProceedsFromStockOptionsExercisedEarlyExercise" xlink:label="loc_qlys_ProceedsFromStockOptionsExercisedEarlyExercise_91895680-8351-5eeb-b625-1fa9efce35f9" xlink:type="locator" />
    <calculationArc order="2" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_a678c20d-a481-ef6a-800a-4bd566075d81" xlink:to="loc_qlys_ProceedsFromStockOptionsExercisedEarlyExercise_91895680-8351-5eeb-b625-1fa9efce35f9" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_ExcessTaxBenefitFromShareBasedCompensationFinancingActivities" xlink:label="loc_us-gaap_ExcessTaxBenefitFromShareBasedCompensationFinancingActivities_9dbeb004-67a9-1b19-c357-8b5cbf0013ee" xlink:type="locator" />
    <calculationArc order="3" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_a678c20d-a481-ef6a-800a-4bd566075d81" xlink:to="loc_us-gaap_ExcessTaxBenefitFromShareBasedCompensationFinancingActivities_9dbeb004-67a9-1b19-c357-8b5cbf0013ee" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_RepaymentsOfLongTermCapitalLeaseObligations" xlink:label="loc_us-gaap_RepaymentsOfLongTermCapitalLeaseObligations_51617b66-bd39-6ab3-80dc-0e2706dd562a" xlink:type="locator" />
    <calculationArc order="4" weight="-1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_a678c20d-a481-ef6a-800a-4bd566075d81" xlink:to="loc_us-gaap_RepaymentsOfLongTermCapitalLeaseObligations_51617b66-bd39-6ab3-80dc-0e2706dd562a" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_EffectOfExchangeRateOnCashAndCashEquivalents" xlink:label="loc_us-gaap_EffectOfExchangeRateOnCashAndCashEquivalents_438c1b09-9f50-5f5e-b6af-87ca1807a1a2" xlink:type="locator" />
    <calculationArc order="4" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease_ff5db18e-7b91-5a5d-e914-0527b02a8012" xlink:to="loc_us-gaap_EffectOfExchangeRateOnCashAndCashEquivalents_438c1b09-9f50-5f5e-b6af-87ca1807a1a2" xlink:type="arc" />
  </calculationLink>
  <calculationLink xlink:role="http://www.qualys.com/role/ConsolidatedStatementsOfComprehensiveIncome" xlink:type="extended">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_ComprehensiveIncomeNetOfTax" xlink:label="loc_us-gaap_ComprehensiveIncomeNetOfTax_640557c9-9806-6bef-9084-9cc792948f77" xlink:type="locator" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_NetIncomeLoss" xlink:label="loc_us-gaap_NetIncomeLoss_e62ce8b8-4401-2622-8598-3e644745e95e" xlink:type="locator" />
    <calculationArc order="1" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_ComprehensiveIncomeNetOfTax_640557c9-9806-6bef-9084-9cc792948f77" xlink:to="loc_us-gaap_NetIncomeLoss_e62ce8b8-4401-2622-8598-3e644745e95e" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_58e3e908-4af5-683d-5a7a-0ca47c8e456d" xlink:type="locator" />
    <calculationArc order="2" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_ComprehensiveIncomeNetOfTax_640557c9-9806-6bef-9084-9cc792948f77" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_58e3e908-4af5-683d-5a7a-0ca47c8e456d" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax" xlink:label="loc_us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax_7a0c4985-9166-79eb-6063-d5e6ffb820df" xlink:type="locator" />
    <calculationArc order="1" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_58e3e908-4af5-683d-5a7a-0ca47c8e456d" xlink:to="loc_us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax_7a0c4985-9166-79eb-6063-d5e6ffb820df" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesNetOfTax" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesNetOfTax_1c4a86dc-184f-b6a9-3882-e4b9077e09ca" xlink:type="locator" />
    <calculationArc order="2" weight="-1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_58e3e908-4af5-683d-5a7a-0ca47c8e456d" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesNetOfTax_1c4a86dc-184f-b6a9-3882-e4b9077e09ca" xlink:type="arc" />
  </calculationLink>
  <calculationLink xlink:role="http://www.qualys.com/role/ConsolidatedStatementsOfIncome" xlink:type="extended">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_NetIncomeLoss" xlink:label="loc_us-gaap_NetIncomeLoss_e62ce8b8-4401-2622-8598-3e644745e95e" xlink:type="locator" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments_f0ea1b66-a9f7-f42c-6882-4cca5faefea1" xlink:type="locator" />
    <calculationArc order="1" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetIncomeLoss_e62ce8b8-4401-2622-8598-3e644745e95e" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments_f0ea1b66-a9f7-f42c-6882-4cca5faefea1" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_OperatingIncomeLoss" xlink:label="loc_us-gaap_OperatingIncomeLoss_0ea1551e-1643-5e21-4c6e-6431fd87aa68" xlink:type="locator" />
    <calculationArc order="1" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments_f0ea1b66-a9f7-f42c-6882-4cca5faefea1" xlink:to="loc_us-gaap_OperatingIncomeLoss_0ea1551e-1643-5e21-4c6e-6431fd87aa68" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_GrossProfit" xlink:label="loc_us-gaap_GrossProfit_ae720951-4a78-255d-8bd1-88ff26a27caf" xlink:type="locator" />
    <calculationArc order="1" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_OperatingIncomeLoss_0ea1551e-1643-5e21-4c6e-6431fd87aa68" xlink:to="loc_us-gaap_GrossProfit_ae720951-4a78-255d-8bd1-88ff26a27caf" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_Revenues" xlink:label="loc_us-gaap_Revenues_ba59260a-e348-d7f8-5375-fde11baf79c1" xlink:type="locator" />
    <calculationArc order="1" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_GrossProfit_ae720951-4a78-255d-8bd1-88ff26a27caf" xlink:to="loc_us-gaap_Revenues_ba59260a-e348-d7f8-5375-fde11baf79c1" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_CostOfRevenue" xlink:label="loc_us-gaap_CostOfRevenue_c0661821-9875-3007-18d3-a24455358c7b" xlink:type="locator" />
    <calculationArc order="2" weight="-1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_GrossProfit_ae720951-4a78-255d-8bd1-88ff26a27caf" xlink:to="loc_us-gaap_CostOfRevenue_c0661821-9875-3007-18d3-a24455358c7b" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_OperatingExpenses" xlink:label="loc_us-gaap_OperatingExpenses_8d80f9f2-ec8e-5a02-2390-b5ea959a18b0" xlink:type="locator" />
    <calculationArc order="2" weight="-1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_OperatingIncomeLoss_0ea1551e-1643-5e21-4c6e-6431fd87aa68" xlink:to="loc_us-gaap_OperatingExpenses_8d80f9f2-ec8e-5a02-2390-b5ea959a18b0" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_ResearchAndDevelopmentExpense" xlink:label="loc_us-gaap_ResearchAndDevelopmentExpense_6a3cb05a-f9c0-32f6-d20f-a948f53d0ee5" xlink:type="locator" />
    <calculationArc order="1" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_OperatingExpenses_8d80f9f2-ec8e-5a02-2390-b5ea959a18b0" xlink:to="loc_us-gaap_ResearchAndDevelopmentExpense_6a3cb05a-f9c0-32f6-d20f-a948f53d0ee5" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_SellingAndMarketingExpense" xlink:label="loc_us-gaap_SellingAndMarketingExpense_4466c9c2-563e-0e4c-244e-504a0a74eee1" xlink:type="locator" />
    <calculationArc order="2" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_OperatingExpenses_8d80f9f2-ec8e-5a02-2390-b5ea959a18b0" xlink:to="loc_us-gaap_SellingAndMarketingExpense_4466c9c2-563e-0e4c-244e-504a0a74eee1" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_GeneralAndAdministrativeExpense" xlink:label="loc_us-gaap_GeneralAndAdministrativeExpense_69f193f1-2583-2a25-604c-cc949229c2d8" xlink:type="locator" />
    <calculationArc order="3" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_OperatingExpenses_8d80f9f2-ec8e-5a02-2390-b5ea959a18b0" xlink:to="loc_us-gaap_GeneralAndAdministrativeExpense_69f193f1-2583-2a25-604c-cc949229c2d8" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_NonoperatingIncomeExpense" xlink:label="loc_us-gaap_NonoperatingIncomeExpense_915682f7-b9cc-2ed3-6852-178ddfcb101f" xlink:type="locator" />
    <calculationArc order="2" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments_f0ea1b66-a9f7-f42c-6882-4cca5faefea1" xlink:to="loc_us-gaap_NonoperatingIncomeExpense_915682f7-b9cc-2ed3-6852-178ddfcb101f" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_InterestExpense" xlink:label="loc_us-gaap_InterestExpense_8d3aa4ad-dbea-9eba-4578-5d3b83ba3bc6" xlink:type="locator" />
    <calculationArc order="1" weight="-1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NonoperatingIncomeExpense_915682f7-b9cc-2ed3-6852-178ddfcb101f" xlink:to="loc_us-gaap_InterestExpense_8d3aa4ad-dbea-9eba-4578-5d3b83ba3bc6" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_InvestmentIncomeInterest" xlink:label="loc_us-gaap_InvestmentIncomeInterest_f41ffc72-ebad-5797-e151-38939dd37877" xlink:type="locator" />
    <calculationArc order="2" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NonoperatingIncomeExpense_915682f7-b9cc-2ed3-6852-178ddfcb101f" xlink:to="loc_us-gaap_InvestmentIncomeInterest_f41ffc72-ebad-5797-e151-38939dd37877" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_OtherNonoperatingIncomeExpense" xlink:label="loc_us-gaap_OtherNonoperatingIncomeExpense_51486ac3-3cfb-dff4-43ca-0d3980775a1d" xlink:type="locator" />
    <calculationArc order="3" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NonoperatingIncomeExpense_915682f7-b9cc-2ed3-6852-178ddfcb101f" xlink:to="loc_us-gaap_OtherNonoperatingIncomeExpense_51486ac3-3cfb-dff4-43ca-0d3980775a1d" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_IncomeTaxExpenseBenefit" xlink:label="loc_us-gaap_IncomeTaxExpenseBenefit_b8dcf191-083d-828d-7b9f-e2d2969b89f4" xlink:type="locator" />
    <calculationArc order="2" weight="-1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetIncomeLoss_e62ce8b8-4401-2622-8598-3e644745e95e" xlink:to="loc_us-gaap_IncomeTaxExpenseBenefit_b8dcf191-083d-828d-7b9f-e2d2969b89f4" xlink:type="arc" />
  </calculationLink>
  <calculationLink xlink:role="http://www.qualys.com/role/ConsolidatedStatementsOfStockholdersEquity" xlink:type="extended" />
  <calculationLink xlink:role="http://www.qualys.com/role/DocumentAndEntityInformation" xlink:type="extended" />
  <calculationLink xlink:role="http://www.qualys.com/role/EmployeeStockAndBenefitPlans" xlink:type="extended" />
  <calculationLink xlink:role="http://www.qualys.com/role/EmployeeStockAndBenefitPlansExpenseDetails" xlink:type="extended" />
  <calculationLink xlink:role="http://www.qualys.com/role/EmployeeStockAndBenefitPlansFairValueAssumptionsStockOptionsDetails" xlink:type="extended" />
  <calculationLink xlink:role="http://www.qualys.com/role/EmployeeStockAndBenefitPlansOptionsOutstandingAndVestedDetails" xlink:type="extended" />
  <calculationLink xlink:role="http://www.qualys.com/role/EmployeeStockAndBenefitPlansPlanInformationDetails" xlink:type="extended" />
  <calculationLink xlink:role="http://www.qualys.com/role/EmployeeStockAndBenefitPlansRestrictedStockDetails" xlink:type="extended" />
  <calculationLink xlink:role="http://www.qualys.com/role/EmployeeStockAndBenefitPlansStockOptionActivityDetails" xlink:type="extended" />
  <calculationLink xlink:role="http://www.qualys.com/role/EmployeeStockAndBenefitPlansTables" xlink:type="extended" />
  <calculationLink xlink:role="http://www.qualys.com/role/FairValueOfFinancialInstruments" xlink:type="extended" />
  <calculationLink xlink:role="http://www.qualys.com/role/FairValueOfFinancialInstrumentsCashAndCashEquivalentsAvailableForSaleSecuritiesRestrictedCashReconciliationDetails" xlink:type="extended">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_AvailableForSaleSecuritiesAmortizedCost" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesAmortizedCost_fc1c6482-bc06-c49d-f5fe-3b9e6e37b9c3" xlink:type="locator" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax_d5cbedb3-d62c-f015-a49f-ef377e438819" xlink:type="locator" />
    <calculationArc order="1" weight="-1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesAmortizedCost_fc1c6482-bc06-c49d-f5fe-3b9e6e37b9c3" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax_d5cbedb3-d62c-f015-a49f-ef377e438819" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax_258c41aa-2b09-923b-df97-cb86ef48f935" xlink:type="locator" />
    <calculationArc order="2" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesAmortizedCost_fc1c6482-bc06-c49d-f5fe-3b9e6e37b9c3" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax_258c41aa-2b09-923b-df97-cb86ef48f935" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_AvailableForSaleSecuritiesCurrent" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesCurrent_222b5a74-9526-7448-da46-fccf1775d7c0" xlink:type="locator" />
    <calculationArc order="3" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesAmortizedCost_fc1c6482-bc06-c49d-f5fe-3b9e6e37b9c3" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesCurrent_222b5a74-9526-7448-da46-fccf1775d7c0" xlink:type="arc" />
  </calculationLink>
  <calculationLink xlink:role="http://www.qualys.com/role/FairValueOfFinancialInstrumentsContractualMaturityDetails" xlink:type="extended">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_AvailableForSaleSecurities" xlink:label="loc_us-gaap_AvailableForSaleSecurities_a6e76a34-fa42-d66f-a2a4-5865ce92446b" xlink:type="locator" />
    <loc xlink:href="qlys-20151231.xsd#qlys_AvailableForSaleSecuritiesDebtAndEquityMaturitiesNextTwelveMonthsFairValue" xlink:label="loc_qlys_AvailableForSaleSecuritiesDebtAndEquityMaturitiesNextTwelveMonthsFairValue_0eb91567-8763-36f2-c391-05e3ed138ef8" xlink:type="locator" />
    <calculationArc order="1" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_AvailableForSaleSecurities_a6e76a34-fa42-d66f-a2a4-5865ce92446b" xlink:to="loc_qlys_AvailableForSaleSecuritiesDebtAndEquityMaturitiesNextTwelveMonthsFairValue_0eb91567-8763-36f2-c391-05e3ed138ef8" xlink:type="arc" />
    <loc xlink:href="qlys-20151231.xsd#qlys_AvailableForSaleSecuritiesDebtAndEquityMaturitiesYearOneThroughTwoFairValue" xlink:label="loc_qlys_AvailableForSaleSecuritiesDebtAndEquityMaturitiesYearOneThroughTwoFairValue_25e96a85-278d-07dd-871d-05e3ed080c5e" xlink:type="locator" />
    <calculationArc order="2" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_AvailableForSaleSecurities_a6e76a34-fa42-d66f-a2a4-5865ce92446b" xlink:to="loc_qlys_AvailableForSaleSecuritiesDebtAndEquityMaturitiesYearOneThroughTwoFairValue_25e96a85-278d-07dd-871d-05e3ed080c5e" xlink:type="arc" />
    <loc xlink:href="qlys-20151231.xsd#qlys_AvailableForSaleSecuritiesDebtAndEquityMaturitiesAfterYearTwoFairValue" xlink:label="loc_qlys_AvailableForSaleSecuritiesDebtAndEquityMaturitiesAfterYearTwoFairValue_064cb8a9-906b-9afa-f03e-05e3ed11461e" xlink:type="locator" />
    <calculationArc order="3" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_AvailableForSaleSecurities_a6e76a34-fa42-d66f-a2a4-5865ce92446b" xlink:to="loc_qlys_AvailableForSaleSecuritiesDebtAndEquityMaturitiesAfterYearTwoFairValue_064cb8a9-906b-9afa-f03e-05e3ed11461e" xlink:type="arc" />
  </calculationLink>
  <calculationLink xlink:role="http://www.qualys.com/role/FairValueOfFinancialInstrumentsFairValueHierarchyDetails" xlink:type="extended" />
  <calculationLink xlink:role="http://www.qualys.com/role/FairValueOfFinancialInstrumentsNarrativeDetails" xlink:type="extended" />
  <calculationLink xlink:role="http://www.qualys.com/role/FairValueOfFinancialInstrumentsTables" xlink:type="extended" />
  <calculationLink xlink:role="http://www.qualys.com/role/GoodwillAndIntangibleAssetsNet" xlink:type="extended" />
  <calculationLink xlink:role="http://www.qualys.com/role/GoodwillAndIntangibleAssetsNetDetails" xlink:type="extended">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_IntangibleAssetsNetExcludingGoodwill" xlink:label="loc_us-gaap_IntangibleAssetsNetExcludingGoodwill_894a128f-2068-d267-1e3e-64c93d0ed5ca" xlink:type="locator" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsNet" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsNet_d1f67248-e9b5-f4cc-7b0f-6057f1a3d17a" xlink:type="locator" />
    <calculationArc order="1" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_IntangibleAssetsNetExcludingGoodwill_894a128f-2068-d267-1e3e-64c93d0ed5ca" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsNet_d1f67248-e9b5-f4cc-7b0f-6057f1a3d17a" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsGross" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsGross_0b66a991-68b5-43d2-3cb3-4ea68bba2b7e" xlink:type="locator" />
    <calculationArc order="1" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsNet_d1f67248-e9b5-f4cc-7b0f-6057f1a3d17a" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsGross_0b66a991-68b5-43d2-3cb3-4ea68bba2b7e" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_5fad788a-33b8-6ace-c3c4-7d91cd9f63e4" xlink:type="locator" />
    <calculationArc order="2" weight="-1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsNet_d1f67248-e9b5-f4cc-7b0f-6057f1a3d17a" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_5fad788a-33b8-6ace-c3c4-7d91cd9f63e4" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill" xlink:label="loc_us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill_37242da4-8bd9-8845-4f04-4d33ee3aa769" xlink:type="locator" />
    <calculationArc order="2" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_IntangibleAssetsNetExcludingGoodwill_894a128f-2068-d267-1e3e-64c93d0ed5ca" xlink:to="loc_us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill_37242da4-8bd9-8845-4f04-4d33ee3aa769" xlink:type="arc" />
  </calculationLink>
  <calculationLink xlink:role="http://www.qualys.com/role/GoodwillAndIntangibleAssetsNetFutureAmortizationDetails" xlink:type="extended">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsNet" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsNet_d1f67248-e9b5-f4cc-7b0f-6057f1a3d17a" xlink:type="locator" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths_2249ecdd-108d-3264-e1fb-82dc2f8b7f93" xlink:type="locator" />
    <calculationArc order="1" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsNet_d1f67248-e9b5-f4cc-7b0f-6057f1a3d17a" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths_2249ecdd-108d-3264-e1fb-82dc2f8b7f93" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo_0395a918-3975-df2b-2aff-c690ea9ff6a6" xlink:type="locator" />
    <calculationArc order="2" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsNet_d1f67248-e9b5-f4cc-7b0f-6057f1a3d17a" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo_0395a918-3975-df2b-2aff-c690ea9ff6a6" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree_522cf592-49df-8430-14fb-ace2b07d08a6" xlink:type="locator" />
    <calculationArc order="3" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsNet_d1f67248-e9b5-f4cc-7b0f-6057f1a3d17a" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree_522cf592-49df-8430-14fb-ace2b07d08a6" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFour" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFour_f9536b4e-5267-6ef8-a509-7c8008810f55" xlink:type="locator" />
    <calculationArc order="4" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsNet_d1f67248-e9b5-f4cc-7b0f-6057f1a3d17a" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFour_f9536b4e-5267-6ef8-a509-7c8008810f55" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFive" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFive_1435205b-5a1f-afbc-0b39-6d638729472e" xlink:type="locator" />
    <calculationArc order="5" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsNet_d1f67248-e9b5-f4cc-7b0f-6057f1a3d17a" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFive_1435205b-5a1f-afbc-0b39-6d638729472e" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseAfterYearFive" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseAfterYearFive_772dc97e-46eb-33c4-ae54-6c479043f6a5" xlink:type="locator" />
    <calculationArc order="6" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsNet_d1f67248-e9b5-f4cc-7b0f-6057f1a3d17a" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseAfterYearFive_772dc97e-46eb-33c4-ae54-6c479043f6a5" xlink:type="arc" />
  </calculationLink>
  <calculationLink xlink:role="http://www.qualys.com/role/GoodwillAndIntangibleAssetsNetTables" xlink:type="extended" />
  <calculationLink xlink:role="http://www.qualys.com/role/IncomeTaxes" xlink:type="extended" />
  <calculationLink xlink:role="http://www.qualys.com/role/IncomeTaxesDeferredTaxAssetsAndLiabilitiesDetails" xlink:type="extended">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_DeferredTaxAssetsLiabilitiesNet" xlink:label="loc_us-gaap_DeferredTaxAssetsLiabilitiesNet_7ab95885-50a1-f3b5-4737-49b616fc51d6" xlink:type="locator" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_DeferredTaxAssetsNet" xlink:label="loc_us-gaap_DeferredTaxAssetsNet_c9103802-e01c-0411-2da8-2206c8e6cbaf" xlink:type="locator" />
    <calculationArc order="1" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_DeferredTaxAssetsLiabilitiesNet_7ab95885-50a1-f3b5-4737-49b616fc51d6" xlink:to="loc_us-gaap_DeferredTaxAssetsNet_c9103802-e01c-0411-2da8-2206c8e6cbaf" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_DeferredTaxAssetsGross" xlink:label="loc_us-gaap_DeferredTaxAssetsGross_ae76b0a4-0e26-3d8f-4ecb-c8186dd802d0" xlink:type="locator" />
    <calculationArc order="1" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_DeferredTaxAssetsNet_c9103802-e01c-0411-2da8-2206c8e6cbaf" xlink:to="loc_us-gaap_DeferredTaxAssetsGross_ae76b0a4-0e26-3d8f-4ecb-c8186dd802d0" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_DeferredTaxAssetsOperatingLossCarryforwards" xlink:label="loc_us-gaap_DeferredTaxAssetsOperatingLossCarryforwards_2388bf7d-bac3-63e4-7ea0-6e9febb628dd" xlink:type="locator" />
    <calculationArc order="1" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_DeferredTaxAssetsGross_ae76b0a4-0e26-3d8f-4ecb-c8186dd802d0" xlink:to="loc_us-gaap_DeferredTaxAssetsOperatingLossCarryforwards_2388bf7d-bac3-63e4-7ea0-6e9febb628dd" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_DeferredTaxAssetsTaxCreditCarryforwardsResearch" xlink:label="loc_us-gaap_DeferredTaxAssetsTaxCreditCarryforwardsResearch_d5eac5d2-09a1-57ad-5162-7ab7e28ad31e" xlink:type="locator" />
    <calculationArc order="2" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_DeferredTaxAssetsGross_ae76b0a4-0e26-3d8f-4ecb-c8186dd802d0" xlink:to="loc_us-gaap_DeferredTaxAssetsTaxCreditCarryforwardsResearch_d5eac5d2-09a1-57ad-5162-7ab7e28ad31e" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAccruedLiabilities" xlink:label="loc_us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAccruedLiabilities_c4ce560b-fd0f-3932-c8de-df83897a8677" xlink:type="locator" />
    <calculationArc order="3" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_DeferredTaxAssetsGross_ae76b0a4-0e26-3d8f-4ecb-c8186dd802d0" xlink:to="loc_us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAccruedLiabilities_c4ce560b-fd0f-3932-c8de-df83897a8677" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_DeferredTaxAssetsDeferredIncome" xlink:label="loc_us-gaap_DeferredTaxAssetsDeferredIncome_2bda83ba-0db3-98b0-761b-d8fe7c271584" xlink:type="locator" />
    <calculationArc order="4" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_DeferredTaxAssetsGross_ae76b0a4-0e26-3d8f-4ecb-c8186dd802d0" xlink:to="loc_us-gaap_DeferredTaxAssetsDeferredIncome_2bda83ba-0db3-98b0-761b-d8fe7c271584" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsDeferredRent" xlink:label="loc_us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsDeferredRent_40627278-dad4-5a0f-329b-5115a45ba8df" xlink:type="locator" />
    <calculationArc order="5" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_DeferredTaxAssetsGross_ae76b0a4-0e26-3d8f-4ecb-c8186dd802d0" xlink:to="loc_us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsDeferredRent_40627278-dad4-5a0f-329b-5115a45ba8df" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_DeferredTaxAssetsGoodwillAndIntangibleAssets" xlink:label="loc_us-gaap_DeferredTaxAssetsGoodwillAndIntangibleAssets_537e4665-5eba-ae94-5fa7-7d9f8b4fe9eb" xlink:type="locator" />
    <calculationArc order="6" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_DeferredTaxAssetsGross_ae76b0a4-0e26-3d8f-4ecb-c8186dd802d0" xlink:to="loc_us-gaap_DeferredTaxAssetsGoodwillAndIntangibleAssets_537e4665-5eba-ae94-5fa7-7d9f8b4fe9eb" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsShareBasedCompensationCost" xlink:label="loc_us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsShareBasedCompensationCost_11af201b-713a-e639-e3e5-2a2e9be5b0c6" xlink:type="locator" />
    <calculationArc order="7" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_DeferredTaxAssetsGross_ae76b0a4-0e26-3d8f-4ecb-c8186dd802d0" xlink:to="loc_us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsShareBasedCompensationCost_11af201b-713a-e639-e3e5-2a2e9be5b0c6" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_DeferredTaxAssetsOther" xlink:label="loc_us-gaap_DeferredTaxAssetsOther_d2894808-c556-546c-7bdb-cf4d5d84446f" xlink:type="locator" />
    <calculationArc order="8" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_DeferredTaxAssetsGross_ae76b0a4-0e26-3d8f-4ecb-c8186dd802d0" xlink:to="loc_us-gaap_DeferredTaxAssetsOther_d2894808-c556-546c-7bdb-cf4d5d84446f" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_DeferredTaxAssetsValuationAllowance" xlink:label="loc_us-gaap_DeferredTaxAssetsValuationAllowance_43429341-a7f8-3d28-8300-64e1feef8fa0" xlink:type="locator" />
    <calculationArc order="2" weight="-1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_DeferredTaxAssetsNet_c9103802-e01c-0411-2da8-2206c8e6cbaf" xlink:to="loc_us-gaap_DeferredTaxAssetsValuationAllowance_43429341-a7f8-3d28-8300-64e1feef8fa0" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_DeferredTaxLiabilities" xlink:label="loc_us-gaap_DeferredTaxLiabilities_f790ef08-9e64-0989-2e62-f1a00cb26d64" xlink:type="locator" />
    <calculationArc order="2" weight="-1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_DeferredTaxAssetsLiabilitiesNet_7ab95885-50a1-f3b5-4737-49b616fc51d6" xlink:to="loc_us-gaap_DeferredTaxLiabilities_f790ef08-9e64-0989-2e62-f1a00cb26d64" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_DeferredTaxLiabilitiesPropertyPlantAndEquipment" xlink:label="loc_us-gaap_DeferredTaxLiabilitiesPropertyPlantAndEquipment_e4e22af7-4d5b-ea8d-3fb7-83c7b5ae1f7b" xlink:type="locator" />
    <calculationArc order="1" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_DeferredTaxLiabilities_f790ef08-9e64-0989-2e62-f1a00cb26d64" xlink:to="loc_us-gaap_DeferredTaxLiabilitiesPropertyPlantAndEquipment_e4e22af7-4d5b-ea8d-3fb7-83c7b5ae1f7b" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_DeferredTaxLiabilitiesGoodwillAndIntangibleAssetsIntangibleAssets" xlink:label="loc_us-gaap_DeferredTaxLiabilitiesGoodwillAndIntangibleAssetsIntangibleAssets_371df7bd-8911-dc61-e047-ba9703021545" xlink:type="locator" />
    <calculationArc order="2" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_DeferredTaxLiabilities_f790ef08-9e64-0989-2e62-f1a00cb26d64" xlink:to="loc_us-gaap_DeferredTaxLiabilitiesGoodwillAndIntangibleAssetsIntangibleAssets_371df7bd-8911-dc61-e047-ba9703021545" xlink:type="arc" />
  </calculationLink>
  <calculationLink xlink:role="http://www.qualys.com/role/IncomeTaxesIncomeBeforeProvisionForBenefitFromIncomeTaxesDetails" xlink:type="extended">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments_f0ea1b66-a9f7-f42c-6882-4cca5faefea1" xlink:type="locator" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic_e8c93fd8-b953-0fac-1368-bda1875af048" xlink:type="locator" />
    <calculationArc order="1" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments_f0ea1b66-a9f7-f42c-6882-4cca5faefea1" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic_e8c93fd8-b953-0fac-1368-bda1875af048" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign_6a037740-99db-8b3b-3911-f1b1e7885e0c" xlink:type="locator" />
    <calculationArc order="2" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments_f0ea1b66-a9f7-f42c-6882-4cca5faefea1" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign_6a037740-99db-8b3b-3911-f1b1e7885e0c" xlink:type="arc" />
  </calculationLink>
  <calculationLink xlink:role="http://www.qualys.com/role/IncomeTaxesNarrativeDetails" xlink:type="extended" />
  <calculationLink xlink:role="http://www.qualys.com/role/IncomeTaxesProvisionForBenefitFromIncomeTaxesDetails" xlink:type="extended">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_IncomeTaxExpenseBenefit" xlink:label="loc_us-gaap_IncomeTaxExpenseBenefit_b8dcf191-083d-828d-7b9f-e2d2969b89f4" xlink:type="locator" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_CurrentIncomeTaxExpenseBenefit" xlink:label="loc_us-gaap_CurrentIncomeTaxExpenseBenefit_34234baa-d101-3f73-2c90-9ccf83248ac9" xlink:type="locator" />
    <calculationArc order="1" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_IncomeTaxExpenseBenefit_b8dcf191-083d-828d-7b9f-e2d2969b89f4" xlink:to="loc_us-gaap_CurrentIncomeTaxExpenseBenefit_34234baa-d101-3f73-2c90-9ccf83248ac9" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_CurrentFederalTaxExpenseBenefit" xlink:label="loc_us-gaap_CurrentFederalTaxExpenseBenefit_bbeff925-a146-2078-8abf-f4cd97255735" xlink:type="locator" />
    <calculationArc order="1" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_CurrentIncomeTaxExpenseBenefit_34234baa-d101-3f73-2c90-9ccf83248ac9" xlink:to="loc_us-gaap_CurrentFederalTaxExpenseBenefit_bbeff925-a146-2078-8abf-f4cd97255735" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_CurrentStateAndLocalTaxExpenseBenefit" xlink:label="loc_us-gaap_CurrentStateAndLocalTaxExpenseBenefit_2ac2b83b-7587-ac08-d667-af95bd01fbb2" xlink:type="locator" />
    <calculationArc order="2" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_CurrentIncomeTaxExpenseBenefit_34234baa-d101-3f73-2c90-9ccf83248ac9" xlink:to="loc_us-gaap_CurrentStateAndLocalTaxExpenseBenefit_2ac2b83b-7587-ac08-d667-af95bd01fbb2" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_CurrentForeignTaxExpenseBenefit" xlink:label="loc_us-gaap_CurrentForeignTaxExpenseBenefit_1be7a3a1-cbc3-8ffe-f157-edb51cd26a68" xlink:type="locator" />
    <calculationArc order="3" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_CurrentIncomeTaxExpenseBenefit_34234baa-d101-3f73-2c90-9ccf83248ac9" xlink:to="loc_us-gaap_CurrentForeignTaxExpenseBenefit_1be7a3a1-cbc3-8ffe-f157-edb51cd26a68" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_DeferredIncomeTaxExpenseBenefit" xlink:label="loc_us-gaap_DeferredIncomeTaxExpenseBenefit_8b437d2d-6bbf-1f71-a341-6d3ac2b36703" xlink:type="locator" />
    <calculationArc order="2" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_IncomeTaxExpenseBenefit_b8dcf191-083d-828d-7b9f-e2d2969b89f4" xlink:to="loc_us-gaap_DeferredIncomeTaxExpenseBenefit_8b437d2d-6bbf-1f71-a341-6d3ac2b36703" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_DeferredFederalIncomeTaxExpenseBenefit" xlink:label="loc_us-gaap_DeferredFederalIncomeTaxExpenseBenefit_0a099f0c-8f61-7b47-fb6f-d9dfccab6a2b" xlink:type="locator" />
    <calculationArc order="1" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_DeferredIncomeTaxExpenseBenefit_8b437d2d-6bbf-1f71-a341-6d3ac2b36703" xlink:to="loc_us-gaap_DeferredFederalIncomeTaxExpenseBenefit_0a099f0c-8f61-7b47-fb6f-d9dfccab6a2b" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_DeferredStateAndLocalIncomeTaxExpenseBenefit" xlink:label="loc_us-gaap_DeferredStateAndLocalIncomeTaxExpenseBenefit_01bd828d-ff2f-1258-4ecb-6afd711760b6" xlink:type="locator" />
    <calculationArc order="2" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_DeferredIncomeTaxExpenseBenefit_8b437d2d-6bbf-1f71-a341-6d3ac2b36703" xlink:to="loc_us-gaap_DeferredStateAndLocalIncomeTaxExpenseBenefit_01bd828d-ff2f-1258-4ecb-6afd711760b6" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_DeferredForeignIncomeTaxExpenseBenefit" xlink:label="loc_us-gaap_DeferredForeignIncomeTaxExpenseBenefit_de4150a6-31ba-55b3-12d4-35cb377c9ca2" xlink:type="locator" />
    <calculationArc order="3" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_DeferredIncomeTaxExpenseBenefit_8b437d2d-6bbf-1f71-a341-6d3ac2b36703" xlink:to="loc_us-gaap_DeferredForeignIncomeTaxExpenseBenefit_de4150a6-31ba-55b3-12d4-35cb377c9ca2" xlink:type="arc" />
  </calculationLink>
  <calculationLink xlink:role="http://www.qualys.com/role/IncomeTaxesTables" xlink:type="extended" />
  <calculationLink xlink:role="http://www.qualys.com/role/IncomeTaxesTaxRateReconciliationDetails" xlink:type="extended">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_EffectiveIncomeTaxRateContinuingOperations" xlink:label="loc_us-gaap_EffectiveIncomeTaxRateContinuingOperations_037594ef-c95d-7169-0f2c-0d9bf9c6587e" xlink:type="locator" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate" xlink:label="loc_us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate_acf5d13d-61d7-58c0-7f7b-a5c0f7cb7066" xlink:type="locator" />
    <calculationArc order="1" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_EffectiveIncomeTaxRateContinuingOperations_037594ef-c95d-7169-0f2c-0d9bf9c6587e" xlink:to="loc_us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate_acf5d13d-61d7-58c0-7f7b-a5c0f7cb7066" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes" xlink:label="loc_us-gaap_EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes_4b3be44f-5687-e783-ac34-c53c5c3f10e0" xlink:type="locator" />
    <calculationArc order="2" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_EffectiveIncomeTaxRateContinuingOperations_037594ef-c95d-7169-0f2c-0d9bf9c6587e" xlink:to="loc_us-gaap_EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes_4b3be44f-5687-e783-ac34-c53c5c3f10e0" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpenseShareBasedCompensationCost" xlink:label="loc_us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpenseShareBasedCompensationCost_89addf3c-f7bf-964a-aba6-4e5ca9958acd" xlink:type="locator" />
    <calculationArc order="3" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_EffectiveIncomeTaxRateContinuingOperations_037594ef-c95d-7169-0f2c-0d9bf9c6587e" xlink:to="loc_us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpenseShareBasedCompensationCost_89addf3c-f7bf-964a-aba6-4e5ca9958acd" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationRepatriationOfForeignEarnings" xlink:label="loc_us-gaap_EffectiveIncomeTaxRateReconciliationRepatriationOfForeignEarnings_22e7e4c3-075c-8540-fe19-205a2056c258" xlink:type="locator" />
    <calculationArc order="4" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_EffectiveIncomeTaxRateContinuingOperations_037594ef-c95d-7169-0f2c-0d9bf9c6587e" xlink:to="loc_us-gaap_EffectiveIncomeTaxRateReconciliationRepatriationOfForeignEarnings_22e7e4c3-075c-8540-fe19-205a2056c258" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance" xlink:label="loc_us-gaap_EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance_ae3561e4-ce43-53a8-871d-507f741a2369" xlink:type="locator" />
    <calculationArc order="5" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_EffectiveIncomeTaxRateContinuingOperations_037594ef-c95d-7169-0f2c-0d9bf9c6587e" xlink:to="loc_us-gaap_EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance_ae3561e4-ce43-53a8-871d-507f741a2369" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationChangeInEnactedTaxRate" xlink:label="loc_us-gaap_EffectiveIncomeTaxRateReconciliationChangeInEnactedTaxRate_61f785a6-a36b-dddb-bd15-1c39edb4e64f" xlink:type="locator" />
    <calculationArc order="6" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_EffectiveIncomeTaxRateContinuingOperations_037594ef-c95d-7169-0f2c-0d9bf9c6587e" xlink:to="loc_us-gaap_EffectiveIncomeTaxRateReconciliationChangeInEnactedTaxRate_61f785a6-a36b-dddb-bd15-1c39edb4e64f" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationTaxCreditsResearch" xlink:label="loc_us-gaap_EffectiveIncomeTaxRateReconciliationTaxCreditsResearch_6bbeca8f-a74f-62c9-14cf-944a068a4d23" xlink:type="locator" />
    <calculationArc order="7" weight="-1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_EffectiveIncomeTaxRateContinuingOperations_037594ef-c95d-7169-0f2c-0d9bf9c6587e" xlink:to="loc_us-gaap_EffectiveIncomeTaxRateReconciliationTaxCreditsResearch_6bbeca8f-a74f-62c9-14cf-944a068a4d23" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationOtherAdjustments" xlink:label="loc_us-gaap_EffectiveIncomeTaxRateReconciliationOtherAdjustments_750737d4-a9f6-ddcb-7238-bbe8eadd7390" xlink:type="locator" />
    <calculationArc order="8" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_EffectiveIncomeTaxRateContinuingOperations_037594ef-c95d-7169-0f2c-0d9bf9c6587e" xlink:to="loc_us-gaap_EffectiveIncomeTaxRateReconciliationOtherAdjustments_750737d4-a9f6-ddcb-7238-bbe8eadd7390" xlink:type="arc" />
  </calculationLink>
  <calculationLink xlink:role="http://www.qualys.com/role/IncomeTaxesUnrecognizedTaxBenefitsDetails" xlink:type="extended" />
  <calculationLink xlink:role="http://www.qualys.com/role/NetIncomePerShareAttributableToCommonStockholders" xlink:type="extended" />
  <calculationLink xlink:role="http://www.qualys.com/role/NetIncomePerShareAttributableToCommonStockholdersDetails" xlink:type="extended">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_NetIncomeLossAvailableToCommonStockholdersDiluted" xlink:label="loc_us-gaap_NetIncomeLossAvailableToCommonStockholdersDiluted_6bff86ee-e32e-51d0-aeda-1599604eacef" xlink:type="locator" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic" xlink:label="loc_us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic_a8aff2a0-5170-c273-e6ae-b3a075237f59" xlink:type="locator" />
    <calculationArc order="1" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetIncomeLossAvailableToCommonStockholdersDiluted_6bff86ee-e32e-51d0-aeda-1599604eacef" xlink:to="loc_us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic_a8aff2a0-5170-c273-e6ae-b3a075237f59" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_NetIncomeLoss" xlink:label="loc_us-gaap_NetIncomeLoss_e62ce8b8-4401-2622-8598-3e644745e95e" xlink:type="locator" />
    <calculationArc order="1" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic_a8aff2a0-5170-c273-e6ae-b3a075237f59" xlink:to="loc_us-gaap_NetIncomeLoss_e62ce8b8-4401-2622-8598-3e644745e95e" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_ParticipatingSecuritiesDistributedAndUndistributedEarningsLossBasic" xlink:label="loc_us-gaap_ParticipatingSecuritiesDistributedAndUndistributedEarningsLossBasic_0f3128f3-3d8b-e700-4bb6-7eb11674f54c" xlink:type="locator" />
    <calculationArc order="2" weight="-1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic_a8aff2a0-5170-c273-e6ae-b3a075237f59" xlink:to="loc_us-gaap_ParticipatingSecuritiesDistributedAndUndistributedEarningsLossBasic_0f3128f3-3d8b-e700-4bb6-7eb11674f54c" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding" xlink:label="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_ca9bebe4-4073-b721-7b75-1a0086593d58" xlink:type="locator" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingBasic" xlink:label="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_8afbf9ec-40f2-ac04-dde9-64f96fdfbf74" xlink:type="locator" />
    <calculationArc order="1" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_ca9bebe4-4073-b721-7b75-1a0086593d58" xlink:to="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_8afbf9ec-40f2-ac04-dde9-64f96fdfbf74" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements" xlink:label="loc_us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements_0449447d-2475-b5e7-892e-ced6d0229840" xlink:type="locator" />
    <calculationArc order="2" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_ca9bebe4-4073-b721-7b75-1a0086593d58" xlink:to="loc_us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements_0449447d-2475-b5e7-892e-ced6d0229840" xlink:type="arc" />
  </calculationLink>
  <calculationLink xlink:role="http://www.qualys.com/role/NetIncomePerShareAttributableToCommonStockholdersTables" xlink:type="extended" />
  <calculationLink xlink:role="http://www.qualys.com/role/OtherIncomeExpenseNet" xlink:type="extended" />
  <calculationLink xlink:role="http://www.qualys.com/role/OtherIncomeExpenseNetDetails" xlink:type="extended">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_OtherNonoperatingIncomeExpense" xlink:label="loc_us-gaap_OtherNonoperatingIncomeExpense_51486ac3-3cfb-dff4-43ca-0d3980775a1d" xlink:type="locator" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_ForeignCurrencyTransactionGainLossBeforeTax" xlink:label="loc_us-gaap_ForeignCurrencyTransactionGainLossBeforeTax_7d95006c-ae0a-39bc-bb82-9715342e9a83" xlink:type="locator" />
    <calculationArc order="1" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_OtherNonoperatingIncomeExpense_51486ac3-3cfb-dff4-43ca-0d3980775a1d" xlink:to="loc_us-gaap_ForeignCurrencyTransactionGainLossBeforeTax_7d95006c-ae0a-39bc-bb82-9715342e9a83" xlink:type="arc" />
    <loc xlink:href="qlys-20151231.xsd#qlys_OtherNonOperatingIncomeExpenseOther" xlink:label="loc_qlys_OtherNonOperatingIncomeExpenseOther_ddb7ac6a-385c-b1a7-4156-05e3ed0c9a79" xlink:type="locator" />
    <calculationArc order="2" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_OtherNonoperatingIncomeExpense_51486ac3-3cfb-dff4-43ca-0d3980775a1d" xlink:to="loc_qlys_OtherNonOperatingIncomeExpenseOther_ddb7ac6a-385c-b1a7-4156-05e3ed0c9a79" xlink:type="arc" />
  </calculationLink>
  <calculationLink xlink:role="http://www.qualys.com/role/OtherIncomeExpenseNetTables" xlink:type="extended" />
  <calculationLink xlink:role="http://www.qualys.com/role/PropertyAndEquipmentNet" xlink:type="extended" />
  <calculationLink xlink:role="http://www.qualys.com/role/PropertyAndEquipmentNetDetails" xlink:type="extended">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_PropertyPlantAndEquipmentNet" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentNet_7ce178a4-245f-fa78-36a1-552609a67554" xlink:type="locator" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_PropertyPlantAndEquipmentGross" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentGross_6591f040-08b3-69a1-a560-c70736475ada" xlink:type="locator" />
    <calculationArc order="1" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentNet_7ce178a4-245f-fa78-36a1-552609a67554" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentGross_6591f040-08b3-69a1-a560-c70736475ada" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd#us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" xlink:label="loc_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_b84a1570-30ad-4e3a-2391-9767a64e15fd" xlink:type="locator" />
    <calculationArc order="2" weight="-1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentNet_7ce178a4-245f-fa78-36a1-552609a67554" xlink:to="loc_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_b84a1570-30ad-4e3a-2391-9767a64e15fd" xlink:type="arc" />
  </calculationLink>
  <calculationLink xlink:role="http://www.qualys.com/role/PropertyAndEquipmentNetTables" xlink:type="extended" />
  <calculationLink xlink:role="http://www.qualys.com/role/QuarterlyFinancialInformationUnaudited" xlink:type="extended" />
  <calculationLink xlink:role="http://www.qualys.com/role/QuarterlyFinancialInformationUnauditedDetails" xlink:type="extended" />
  <calculationLink xlink:role="http://www.qualys.com/role/QuarterlyFinancialInformationUnauditedTables" xlink:type="extended" />
  <calculationLink xlink:role="http://www.qualys.com/role/ScheduleIiScheduleOfValuationAndQualifyingAccounts" xlink:type="extended" />
  <calculationLink xlink:role="http://www.qualys.com/role/ScheduleIiScheduleOfValuationAndQualifyingAccountsDetails" xlink:type="extended" />
  <calculationLink xlink:role="http://www.qualys.com/role/SegmentInformationAndInformationAboutGeographicArea" xlink:type="extended" />
  <calculationLink xlink:role="http://www.qualys.com/role/SegmentInformationAndInformationAboutGeographicAreaDetails" xlink:type="extended" />
  <calculationLink xlink:role="http://www.qualys.com/role/SegmentInformationAndInformationAboutGeographicAreaTables" xlink:type="extended" />
  <calculationLink xlink:role="http://www.qualys.com/role/StockholdersEquity" xlink:type="extended" />
  <calculationLink xlink:role="http://www.qualys.com/role/StockholdersEquityDetails" xlink:type="extended" />
  <calculationLink xlink:role="http://www.qualys.com/role/StockholdersEquityTables" xlink:type="extended" />
</linkbase>
