How much downtime is 99.9% uptime?
Pick a percentage and a period to see how much downtime it allows, in hours, minutes and seconds. Uptime is usually promised as a share of a month or a year, not as a number of minutes.
Allowed downtime
- Year (365 days)
- 8 h 45 m 36 s
- Day
- 1 m 26 s
- Week
- 10 m 5 s
- Month (30 days)
- 43 m 12 s
| Target | Day | Week | Month (30 days) | Year (365 days) |
|---|---|---|---|---|
| 99% | 14 m 24 s | 1 h 40 m 48 s | 7 h 12 m 0 s | 3 d 15 h 36 m 0 s |
| 99.5% | 7 m 12 s | 50 m 24 s | 3 h 36 m 0 s | 1 d 19 h 48 m 0 s |
| 99.9% | 1 m 26 s | 10 m 5 s | 43 m 12 s | 8 h 45 m 36 s |
| 99.95% | 43 s | 5 m 2 s | 21 m 36 s | 4 h 22 m 48 s |
| 99.99% | 9 s | 1 m 0 s | 4 m 19 s | 52 m 34 s |
How to read this
- Allowed downtime
- How much a period may be down and still meet the target, in hours, minutes and seconds.
- Common targets
- The uptime percentages providers usually promise, from 99% to four nines.
Questions
Does this call my server?
No. It only does arithmetic on the percentage and period you pick.
Where do the common targets come from?
They are the uptime percentages providers usually promise, from 99% up to four nines.
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