How much downtime does 99.5% uptime allow?
99.5% uptime allows 1d 19h 48m of downtime per year. Here is the full budget, by period.
| Per day | 7m 12s |
| Per week | 50m 24s |
| Per month | 3h 36m |
| Per quarter | 10h 48m |
| Per year | 1d 19h 48m |
Is 99.5% the right target?
99.5% sits between a casual target and a true SLA. It suits growing SaaS products and B2B tools that need better than 99% but have not yet committed to a contractual 99.9%. It is a sensible interim goal while you build redundancy.
What it takes to hold 99.5%
Redundant application instances behind a load balancer, plus alerting that reaches on-call quickly. The roughly 3.5-hour monthly budget means you need to recover from most incidents in well under an hour.
Where you’ll see 99.5%
- A growing B2B SaaS tool before its first contractual SLA
- A content platform with steady but non-mission-critical traffic
- An internal API other teams depend on
Each additional nine cuts the allowed downtime by roughly tenfold. The chart below shows where 99.5% 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 99.5% uptime?
- 99.5% uptime allows about 1 day 19 hours per year — roughly 3 hours 36 minutes per month, or 7 minutes per day. It is noticeably tighter than 99% but still not a five-nines-grade commitment.
- Is 99.5% good enough to offer an SLA?
- It is a reasonable internal target, but most published SaaS SLAs land at 99.9%. Use 99.5% as a stepping stone: prove you can hold it, add automated failover, then promise 99.9% to customers.
- How do I monitor a service to 99.5%?
- Detect fast and confirm before alerting. PingInsight's sub-minute checks (down to one second) catch breaches early, and multi-location quorum plus a consecutive-failure threshold keep alerts trustworthy.
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 | 7m 12s |
| Per week | 50m 24s |
| Per month | 3h 36m |
| Per quarter | 10h 48m |
| Per year | 1d 19h 48m |
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.