SLA Uptime Calculator
Check how much downtime is allowed for your Service Level Agreement (SLA).
Enter your target uptime
Or choose a common SLA below.
%
Allowed Downtime
Daily1m 26s
Weekly10m 4s
Monthly43m 49s
Yearly8h 45m 56s
Need to hit 99.9% uptime?
The only way to ensure high availability is to know immediately when things break.
Monitor Uptime for FreeUnderstanding "The Nines"
In Site Reliability Engineering (SRE), uptime is often referred to by the "number of nines". Each additional nine represents an order of magnitude increase in availability—and difficulty.
- 99% ("Two Nines"): Common for non-critical internal tools. Allows ~3.65 days of downtime per year.
- 99.9% ("Three Nines"): The industry standard for most SaaS products. Allows ~8.76 hours of downtime per year.
- 99.99% ("Four Nines"): High availability for critical infrastructure. Allows only ~52 minutes of downtime per year.
- 99.999% ("Five Nines"): The holy grail. Telco-grade reliability. Allows only ~5 minutes of downtime per year.
How to Calculate Uptime
Uptime is calculated as: (Total Time - Downtime) / Total Time * 100. To maintain a specific SLA, you must minimize your Mean Time To Recovery (MTTR).