SLA / Uptime Calculator
Convert between SLA percentages and allowed downtime, or turn observed downtime into an achieved uptime figure.
Allowed Downtime
| Period | Allowed Downtime | Seconds |
|---|---|---|
| Daily | — | — |
| Weekly | — | — |
| Monthly | — | — |
| Quarterly | — | — |
| Yearly | — | — |
Achieved Uptime
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What is an SLA?
A Service Level Agreement (SLA) is a commitment to keep a service available for a given percentage of time. A Service Level Objective (SLO) is the internal target that feeds that commitment. Uptime is typically expressed in “nines” — three nines (99.9%) allows about 43 minutes of downtime per month, while four nines (99.99%) cuts that to under 5 minutes.
The Nines
| SLA | Downtime / month | Downtime / year | Typical use |
|---|---|---|---|
99% | 7h 18m 30s | 3d 15h 39m | Non-critical internal tools |
99.5% | 3h 39m 15s | 1d 19h 49m | Basic web services |
99.9% | 43m 49.8s | 8h 45m 57s | Most SaaS products |
99.95% | 21m 54.9s | 4h 22m 58s | Business-critical APIs |
99.99% | 4m 23s | 52m 35.7s | Enterprise-grade systems |
99.999% | 26.3s | 5m 15.6s | Telecom, banking, infra |
Monthly figures use the average month length of 30.4375 days (730.5 hours), which matches the convention used in most cloud-provider SLAs (AWS, Google Cloud, Azure).