How do I calculate uptime percentage?

Last updated 5 July 2026

Uptime percentage is uptime divided by total time, times 100. Over a 30-day month (43,200 minutes), 43 minutes of downtime is about 99.9%. The detail that matters is what you count as down: which components, and whether planned maintenance is excluded. Be consistent and state your method, because an inconsistent number is worse than a modest honest one.