Free SLA downtime calculator. Convert SLA percentage to allowed downtime, calculate SLA from actual downtime, and check compliance. Supports all nines (99.9%, 99.99%, 99.999%) with yearly, monthly, and daily breakdowns.
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Service Level Agreements (SLAs) guarantee specific uptime percentages. This calculator converts SLA percentages to allowed downtime, calculates what SLA your actual uptime achieves, and checks if you're meeting your SLA commitments.
SLA uptime percentages determine how much downtime is acceptable. The famous "nines" terminology describes reliability: 99.9% (three nines) allows about 8.77 hours of downtime per year, while 99.999% (five nines) allows only 5.26 minutes per year.
SLA Formula
Downtime = (100% - SLA%) × Total Time PeriodKnow exactly how much downtime your SLA allows per year, month, or day.
Check if your actual uptime meets your SLA commitments and avoid penalties.
Schedule maintenance within your allowed downtime budget.
Understand the real difference between 99.9% and 99.99% SLA tiers.
Compare AWS (99.99%), Azure (99.95%), and Google Cloud SLAs in real downtime minutes.
A 99.9% monthly SLA allows 43.8 minutes of planned downtime per month.
After an outage, check if you've breached your SLA and by how much.
Understand what upgrading from 99.9% to 99.99% actually means in practice.
99.9% (three nines) allows 8.77 hours of downtime per year. 99.99% (four nines) allows only 52.6 minutes per year—a 10x improvement. Each additional nine reduces allowed downtime by a factor of 10.
Most providers measure uptime monthly. If your SLA is 99.9% monthly, you're allowed about 43.8 minutes of downtime each month, not averaged over the year.
It depends on your contract. Many enterprise SLAs exclude pre-announced maintenance windows, while others count all downtime. Always check your specific agreement.
Typically, the provider offers service credits (10-100% of monthly fees for that service). However, credits are usually capped and rarely cover actual business losses from downtime.
Mathematically impossible to guarantee. Even "five nines" (99.999%) allows 5.26 minutes of downtime yearly. True 100% would require infinite redundancy and zero maintenance.