SLA math
99.999%
Five nines is a telephony-era slogan. Most product teams should not print it unless the architecture and staffing already match.
- Per year
- 5 minutes
- Per month
- 0.4 minutes
- Per day (avg)
- 1 seconds
5.3 minutes a year. A single incident is the year. Most SaaS should not print this; the number is the warning, not a target to chase with a status-page tool.
Who uses it
Who usually picks 99.999%
Rare outside regulated or carrier-grade systems. Prefer honest three or four nines plus transparent status history.
Caveats
Read this before you print it on a sales slide
- A single bad deploy can spend the yearly budget
- Measuring five nines requires probes and process most startups do not have
- Customers prefer truthful 99.9% + great communication over fictional five nines
FAQ
99.999% uptime, answered
Exact minutes for five nines, why most SaaS should not promise it, and what to publish instead.
Keep reading
Nearby numbers
Downtime cost calculator
Turn outage minutes into dollars.
99.99% uptime
53 minutes / year
99.95% uptime
4.4 hours / year
Do not print five nines
Print a number you can keep, and a status history customers can read. Start free — consensus checks and a status page on your domain.