TLS certificate lifetime calculator

CA/B Forum public max: 200 days now, 100 days from 15 March 2027, 47 days from 15 March 2029.

Enter a certificate’s notBefore (issue date). We show how many renewals that year-cap implies for 2026, 2027 and 2029: ceil(365 / max lifetime that year).

Issued on Calculate Use last check

Check a live certificate

The 398-day historical maximum ended on 15 March 2026. This page uses the current public max of 200 days for 2026. Share this view with ?issued=YYYY-MM-DD.