| Target | Day | Week | 30 days | Quarter (91 days) | Year (365 days) |
|---|---|---|---|---|---|
| 99% | 14 min 24 s | 1 h 40 min | 7 h 12 min | 21 h 50 min | 3 d 15 h |
| 99.5% | 7 min 12 s | 50 min 24 s | 3 h 36 min | 10 h 55 min | 1 d 19 h |
| 99.9% | 1 min 26 s | 10 min 5 s | 43 min 12 s | 2 h 11 min | 8 h 45 min |
| 99.95% | 43 s | 5 min 2 s | 21 min 36 s | 1 h 5 min | 4 h 22 min |
| 99.99% | 9 s | 1 min | 4 min 19 s | 13 min 6 s | 52 min 34 s |
| 99.999% | 864 ms | 6 s | 26 s | 1 min 19 s | 5 min 15 s |
Downtime is (100 − target) ÷ 100 × the period. A month here is 30 days.
Questions
How much downtime does 99.9% uptime allow?
About 43 min 12 s per 30 days, or 8 h 45 min per year.
How much downtime does 99.99% uptime allow?
About 4 min 19 s per 30 days, or 52 min 34 s per year.