Uptime Calculator
Convert downtime to uptime percentage. Understand your actual availability.
Your Uptime
6 nines
Total Downtime
0s
out of 1 Month
SLA Reference Table
| Uptime % | Nines | Yearly Downtime | Monthly Downtime |
|---|---|---|---|
| 99.999% | 5 | 5.26m | 26.3s |
| 99.99% | 4 | 52.6m | 4.38m |
| 99.9% | 3 | 8.76h | 43.8m |
| 99% | 2 | 3.65d | 7.31h |
| 95% | 1 | 18.25d | 1.52d |
Understanding Uptime
Uptime percentage represents how much of the time your service was available. It's the inverse of downtime and a critical metric for SLA compliance and service reliability.
How it's calculated
Uptime % = (Total Time - Downtime) / Total Time × 100. For example, if you had 4.38 minutes of downtime in a month (30 days), your uptime would be 99.99%.
Why it matters
- SLA compliance - Most SLAs require specific uptime percentages (99.9%, 99.99%)
- Performance reporting - Track and report your actual availability to stakeholders
- Capacity planning - Understand how incidents impact your overall reliability
Frequently Asked Questions
What's the difference between uptime and availability?
They're often used interchangeably. Technically, uptime measures when a system is running, while availability considers whether it's functioning correctly. A slow, unresponsive system may be 'up' but not 'available'.
How do I achieve 99.99% uptime?
99.99% ('four nines') allows only 52.6 minutes of downtime per year. This requires redundancy, automated failover, thorough testing, and rapid incident response. Most achieve this through cloud infrastructure and proactive monitoring.
Should I count scheduled maintenance as downtime?
It depends on your SLA definition. Some SLAs exclude planned maintenance windows from downtime calculations. Be clear with stakeholders about what counts as 'downtime' in your metrics.
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