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  <link:roleRef roleURI="http://www.fortinet.com/role/ScheduleIIValuationandQualifyingAccountsDetails" xlink:type="simple" xlink:href="ftnt-20201231.xsd#ScheduleIIValuationandQualifyingAccountsDetails"/>
  <link:calculationLink xlink:role="http://www.fortinet.com/role/ScheduleIIValuationandQualifyingAccountsDetails" xlink:type="extended"/>
</link:linkbase>
