Uptime SLA Calculator
Convert any SLA percentage into real allowed downtime — per day, week, month, and year. Includes a reference table for 99% through 99.999% (five nines) with exact downtime budgets.
Per Day
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Per Week
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Per Month
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Per Year
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Common SLA Tiers — Allowed Downtime
| SLA | Per Day | Per Week | Per Month | Per Year |
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Know your SLA — then enforce it
Monitor uptime, not just calculate it
MonitorGiant tracks real-time uptime, response times, and SLA compliance across your infrastructure — so you know the moment a downtime budget is being spent.
Disclaimer: Free tool provided “as is” by MonitorGiant. No warranty or liability for any data loss, security issues, or infrastructure problems arising from use of this tool. Results are for informational purposes only. · A Free Tool by MonitorGiant
What is Uptime SLA Calculator?
An SLA (Service Level Agreement) percentage represents the guaranteed proportion of time a system will be available over a given period. A 99.9% SLA sounds impressive, but it allows 8 hours 45 minutes of downtime per year. This calculator converts any SLA percentage into concrete downtime budgets — per day, week, month, and year — so you can plan maintenance windows, set realistic expectations with customers, and understand your error budget.
How to use this tool
- 1 Type any SLA percentage into the input field — from 90% to 99.999%. Or click one of the quick preset buttons for common SLA tiers.
- 2 Read the four result cards showing the maximum allowed downtime for that SLA per day, week, month, and year.
- 3 The tier badge identifies where your SLA falls: two nines (basic), three nines (standard production), four nines (high-availability), or five nines (carrier-grade).
- 4 The error budget note shows your monthly allowance in both formatted time and raw minutes — useful for incident post-mortems.
- 5 The reference table at the bottom shows all six common SLA tiers side-by-side for quick comparison during contract negotiations.
When would you use this?
- Negotiating SLAs with customers or vendors — knowing that 99.9% allows nearly 9 hours of annual downtime changes the conversation.
- Planning maintenance windows — verify your scheduled downtime fits within your committed SLA error budget before scheduling.
- Incident post-mortems — calculate how much of your monthly error budget was consumed by a specific outage duration.
Knowing your SLA budget is step one. MonitorGiant is step two — real-time uptime monitoring that alerts you the moment downtime starts eating into that budget.
How works
- 1
Enter your SLA
Type any percentage or click a preset. The calculator handles everything from 90% (36 days downtime/year) to 99.999% (5 minutes 15 seconds/year).
- 2
Read your downtime budget
Four cards show allowed downtime per day, week, month, and year. The tier badge benchmarks your SLA against industry standards.
- 3
Use the reference table
Compare the six most common SLA tiers side by side — useful for contract discussions and capacity planning.
All calculations are performed locally in your browser. No data is sent to any server.
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