How much downtime does your SLA allow?
Type an availability target and see the downtime budget per day, week, month and year.
Allowed downtime updates as you type.
- Per day
- 1m 26s
- Per week
- 10m 5s
- Per month
- 43m 50s
- Per year
- 8h 45m 58s
Downtime per number of nines
| Availability | Per day | Per week | Per month | Per year |
|---|---|---|---|---|
| 90% | 2h 23m 60s | 16h 47m 60s | 3d 1h 3m | 36d 12h 35m |
| 95% | 1h 12m | 8h 24m | 1d 12h 31m | 18d 6h 18m |
| 99% | 14m 24s | 1h 40m 48s | 7h 18m 20s | 3d 15h 39m |
| 99.5% | 7m 12s | 50m 24s | 3h 39m 10s | 1d 19h 49m |
| 99.9% | 1m 26s | 10m 5s | 43m 50s | 8h 45m 58s |
| 99.95% | 43s | 5m 2s | 21m 55s | 4h 22m 59s |
| 99.99% | 9s | 1m | 4m 23s | 52m 36s |
| 99.995% | 4s | 30s | 2m 12s | 26m 18s |
| 99.999% | 864ms | 6s | 26s | 5m 16s |
A month is 30.44 days, a year 365.25 days.
Uptime and SLAs
How much downtime is 99.9% uptime?
99.9% (three nines) allows about 43 minutes and 50 seconds of downtime a month, 10 minutes a week, or 8 hours and 46 minutes a year.
How much downtime is 99.99% uptime?
99.99% (four nines) allows about 4 minutes and 23 seconds a month, 1 minute a week, or 52 minutes and 36 seconds a year. Few teams reach it without automated failover.
How is uptime measured?
A monitor checks the service at a fixed interval, for example every 30 seconds. Uptime is the share of checks that succeeded over a period. Shorter intervals catch short outages that longer ones miss.
Does planned maintenance count as downtime?
That depends on your SLA. Most SLAs exclude maintenance announced in advance. Pause your monitors or announce a maintenance window on your status page so it's clear to your customers.
Measure it, don't guess it.
Spectate checks every 30 seconds and reports uptime per day, month and year, with the downtime report ready for your SLA.