SLA math

99.95% uptime: the step between three and four nines

Half the downtime budget of 99.9%. Teams pick it when three nines feels soft but four nines is not yet funded.

Target

99.95%

Allowed downtime / year

4.4 hours / year

Per month (avg)

21.9 minutes

Who uses it

Who usually picks 99.95%

Growing products with paying customers who notice multi-hour incidents.

Caveats

Read this before you print it on a sales slide

  • Harder than 99.9% once you count deploys and dependency failures
  • Needs faster detection and clearer paging — not just a nicer status page

FAQ

99.95% uptime, answered

Exact minutes for 99.95%, when to pick it over 99.9%/99.99%, and how fast checks should be.

Keep reading

Related SLA and cost tools

Defend 99.95% with clearer pages

False pages waste the people who keep a 99.95% promise. Tallwatch opens incidents when at least two regions agree — Free includes consensus.