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SLA / uptime calculator

Enter any uptime target and see exactly how much downtime it allows per day, week, month, and year. No account required.

99.9% uptime allows

Per day
1m 26s
Per week
10m 4s
Per month
43m 47s
Per year
8h 45m

“Per month” uses a 365/12-day average month, so twelve months of downtime always add up to one year of downtime. A 28, 30, or 31-day calendar month allows a slightly different figure.

The common SLA targets, at a glance

These are the uptime figures most contracts and status pages actually quote, sometimes called “the nines.” Each links to its own page with the full day/week/month/year breakdown.

TargetNicknameDowntime / monthDowntime / year
99%two nines7h 18m3d 15h
99.5%two and a half nines3h 39m1d 19h
99.9%three nines43m 47s8h 45m
99.95%three and a half nines21m 53s4h 22m
99.99%four nines4m 22s52m 33s
99.999%five nines26 seconds5m 15s

What does that downtime actually cost?

A downtime budget in minutes is one thing; what those minutes cost your business is another. The downtime cost calculator turns a downtime figure (from this page, or a real incident) into an estimated dollar figure using your own revenue.

Know your budget. Now know if you’re inside it.

This tool answers a question of pure arithmetic: what a target allows on paper. Whether you are actually hitting it is a measurement question. RealUptime Monitor checks your endpoints from four live regions on a schedule and reports your real, measured uptime against whatever target you set.

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