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Uptime & SLA Calculator

Enter an uptime percentage to see exactly how much downtime is allowed per year, month, week, day, and hour. Essential for SLA negotiation and reliability planning.

3.0 nines
90%99%99.9%99.99%100%

Allowed Downtime

99.9% uptime
Per year8h 46m
Per month43m 50s
Per week10m 05s
Per day1m 26s
Per hour3.60 s

Quick Reference — Downtime per Year

99%3d 15h 36m
99.5%1d 19h 48m
99.9%8h 45m 36s
99.99%52m 33s
99.999%5m 15s
99.9999%31.5s
  • 100% free — no account needed
  • Runs in your browser
  • Nothing is uploaded

Frequently asked questions

Is Uptime & SLA Calculator really free?

Yes. Uptime & SLA Calculator is completely free on PureBrowser — every feature, with no account, no trial, and no credit card.

Does Uptime & SLA Calculator upload my data?

No. Uptime & SLA Calculator runs entirely inside your browser, so anything you type, paste, or open stays on your own device.

Do I need to sign up or install anything?

Neither. There is no account and nothing to download — open the page and Uptime & SLA Calculator is ready to use on desktop or mobile.

Does Uptime & SLA Calculator work offline?

Once the page has loaded, yes. All of the processing happens locally in your browser, so it keeps working without a connection.

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