Math / CALCULATOR

Uptime and Allowed Downtime

Uptime and Allowed Downtime: explore an explicit model with input checks, a formula and a worked example.

Runs on your deviceUpdates as you typeFormula & example ↓
01

Your inputs

Adjust the values to explore a different result.

days
Enter observation period in days.
min
Enter observed downtime in min.
%
Enter target uptime in %.

Formula

availability=100(1−downtime/period); allowed downtime=period(1−target/100).
  • Use the units shown beside each field.
  • Results update automatically whenever you change an input.
  • Displayed values use up to four decimal places, or scientific notation for very small or large numbers. Calculations use standard floating-point arithmetic; exact integer and fraction tools identify their own precision rules.
  • Time-based availability only. Contract exclusions, partial outages and request-based SLIs are not modeled.

Example Calculation

Example inputs
  • Observation period: 30 days
  • Observed downtime: 60 min
  • Target uptime: 99.9 %

60 minutes down in 30 days gives 99.8611% uptime; a 99.9% target allows 43.2 minutes.

Frequently asked questions

How do I use this calculator?

Enter observation period, observed downtime, target uptime. The result updates automatically. Use Reset to restore the example values.

What method does it use?

availability=100(1−downtime/period); allowed downtime=period(1−target/100).. Time-based availability only. Contract exclusions, partial outages and request-based SLIs are not modeled.

Why might a rounded result differ?

The calculation keeps full numeric precision internally, then rounds the displayed result. Rounding intermediate steps by hand can produce a slightly different answer.

Are my inputs saved online?

No. This calculator processes your inputs in your browser. A recently used list stores only calculator names on this device, not your entered values.

Check the assumptions and units before using this result. Read about calculation methods.