Uptime & SLA Calculator

Translate availability promises into real downtime budgets. Compare 99%, 99.9%, 99.95%, 99.99%, and custom targets, then calculate your actual uptime from incidents, maintenance windows, and outages.

Downtime budgets Actual uptime calculator Incident tracker Client-side only

Availability target

Pick a common uptime tier or enter your own target. Budgets update instantly across common time windows.

Allowed downtime / month
Allowed downtime / year
Error budget used0%
Actual uptime
Window Max downtime As decimal availability Error budget
Rule of thumb: every extra 9 gets dramatically more expensive. Three nines allows 43m 49s of downtime per month. Four nines cuts that to 4m 19s.

Incident-based uptime

Track outages for the selected period. You can paste lines like API outage, 34, unplanned or add them one by one.

Counted downtime0m
Ignored maintenance0m
Remaining budget
SLA status
No incidents added yet.
Add outages to see whether your current period still meets the target.
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