Uptime and SLA calculator
Enter an availability percentage to see the downtime it allows, or enter the downtime in a month to see the availability.
99.9% availability allows
- Per day
- 1 min 26 s
- Per week
- 10 min 5 s
- Per month
- 43 min 50 s
- Per quarter
- 2 h 11 min
- Per year
- 8 h 46 min
Common SLA levels
| Availability | Per month | Per year |
|---|---|---|
| 99% | 7 h 18 min | 3 d 15 h |
| 99.5% | 3 h 39 min | 1 d 19 h |
| 99.9% (DediGermany network SLA) | 43 min 50 s | 8 h 46 min |
| 99.95% | 21 min 55 s | 4 h 23 min |
| 99.99% | 4 min 23 s | 52 min 36 s |
| 99.999% | 26.3 s | 5 min 16 s |
A month is counted as 30.44 days (the average month), a year as 365.25 days.
How availability is calculated
Allowed downtime = period × (100% − availability). For 99.9% over an average month of 30.44 days that is 0.1% of 43,830 minutes: about 43 minutes and 50 seconds. Each extra nine cuts the allowed downtime by ten: 99.99% allows about 4 minutes a month, 99.999% about 26 seconds.
An SLA usually measures one specific thing over a calendar month. DediGermany's SLA covers 99.9% monthly network availability for every dedicated server, measured as the ability of your server's port to pass traffic to the internet. Planned maintenance and problems inside your own server are normally excluded; the SLA page has the details.
Getting more nines
A single server is limited by its hardware: a failed disk or power supply means a repair. For higher availability, run two servers with replication and a load balancer or failover IP, and keep backups somewhere else. Two independent 99.9% servers in parallel can reach well over 99.99% for the service as a whole.
Questions
How much downtime is 99.9% uptime?
About 43 minutes 50 seconds a month, 1 minute 26 seconds a day, or 8 hours 46 minutes a year.
How much downtime is 99.99%?
About 4 minutes 23 seconds a month, or 52 minutes 36 seconds a year.
What does DediGermany's SLA cover?
99.9% monthly network availability for every dedicated server. See the SLA page for how it is measured, what is excluded and how credits work.
Why does the calculator use 30.44 days for a month?
It is the average length of a month (365.25 ÷ 12). For a 30-day month the allowed downtime is about 1% lower, for a 31-day month about 2% higher.
Not sure which server fits?
Tell us what you want to run. We reply around the clock, usually within the hour.