How much downtime does 99.999% uptime allow?
99.999% (five nines) uptime allows 5m 15s of downtime per year. Here is the full budget, by period.
| Per day | 1s |
| Per week | 6s |
| Per month | 26s |
| Per quarter | 1m 18s |
| Per year | 5m 15s |
Is 99.999% (five nines) the right target?
Five nines is telecom-grade and rarely promised by general SaaS. It belongs to telecom networks, critical infrastructure, and core financial systems — services where even a few minutes of downtime a year is unacceptable.
What it takes to hold 99.999%
Active-active redundancy across regions, sub-minute automated failover, and relentless error-budget engineering. With roughly 5 minutes per year, humans cannot be in the recovery loop — failover has to be automatic.
Where you’ll see 99.999%
- A telecom voice or messaging network
- A core banking or trading backend
- Emergency or critical-infrastructure services
Each additional nine cuts the allowed downtime by roughly tenfold. The chart below shows where 99.999% sits relative to the other common uptime targets — and why detection speed, not just the headline percentage, decides whether you actually hold the line.
Frequently asked questions
- How much downtime is 99.999% uptime?
- 99.999% uptime allows about 5 minutes 15 seconds per year — only around 26 seconds per month. Recovery must be automatic; no human can respond inside that window.
- Can a SaaS product realistically offer five nines?
- Very few do, and those that do invest heavily in active-active, multi-region architecture. For most software, five nines is more expensive to engineer than the downtime it prevents is worth.
- How do I monitor a service to 99.999%?
- Measurement has to be precise to the second. PingInsight checks every second and stamps outage timelines to the millisecond, so you can verify whether a five-nines budget was actually met.
Compare every tier on the full uptime / SLA calculator, read what “three nines” really means, or see how 1-second uptime monitoring helps you stay inside this budget.
| Period | Allowed downtime |
|---|---|
| Per day | 1s |
| Per week | 6s |
| Per month | 26s |
| Per quarter | 1m 18s |
| Per year | 5m 15s |
Detection matters as much as the budget. With 5-minute monitoring you can burn minutes of this allowance before you even detect an outage. PingInsight's true 1-second checks catch it almost immediately.
Back to the full uptime calculator or see how 1-second checks help you stay within budget.