SLA Uptime Calculator
See how much downtime an uptime percentage allows per day, week, 30-day month and year, from 99% to 99.999% and anything in between.
- Free
- No sign-up to try
- Works as you type
SLA uptime and allowed downtime
Allowed downtime per 30-day month
43.20 min
Allowed downtime per day
86.4 s
Allowed downtime per week
10.08 min
Allowed downtime per 365-day year
8.76 h
- Allowed downtime = (100% − SLA) × the length of the period.
- A day is 86,400 seconds, a week 10,080 minutes, a 30-day month 43,200 minutes and a 365-day year 8,760 hours.
Free, no sign-up to try. Save it as a live calculator you can share; an estimate from the numbers you enter, not financial advice. Check the result against your own records before you rely on it.
How it works
How the SLA Uptime Calculator works
- 1
Enter your numbers
Every result updates as you type, with the formula shown under it.
- 2
Check the method
See how each number is worked out and what it assumes.
- 3
Save it as a Room
Share a live calculator: others can change the numbers and see the result update.
Worked example
What it makes
Example inputs
- Uptime SLA
- 99.9 %
Results
- Allowed downtime per 30-day month
- 43.20 min
- Allowed downtime per day
- 86.4 s
- Allowed downtime per week
- 10.08 min
- Allowed downtime per 365-day year
- 8.76 h
How it's calculated
- Allowed downtime = (100% − SLA) × the length of the period.
- A day is 86,400 seconds, a week 10,080 minutes, a 30-day month 43,200 minutes and a 365-day year 8,760 hours.
- Assumes: Your contract decides what counts: planned maintenance, partial outages and the measurement window may be excluded or defined differently.
An estimate from the numbers you enter, not financial advice. Check the result against your own records before you rely on it.
Who it's for
Who uses it
Engineering teams
Turn an SLA into an error budget people can picture.
Account managers
Explain what an uptime promise means to a client.
Buyers
Compare the downtime two vendors' SLAs allow.
Good to know
What to consider
- Contracts define what counts: planned maintenance and partial outages are often excluded, and the measurement window may differ.
Questions
About the SLA Uptime Calculator
How much downtime does 99.9% allow?
About 43 minutes in a 30-day month, or about 8.8 hours in a year. Each extra nine cuts the allowance by ten times.
Can I share the calculator with my team or a client?
Yes. The Room keeps the calculator live: anyone with the link can change the numbers and see the result update, with the method and assumptions on the same page.
Make your calculator now
Free, no sign-up to try. It becomes a Room you can edit, publish and share.
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