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Uptime Calculator

Utility

Free online uptime calculator. Convert SLA percentages to downtime per year, month, week, and day. Plan availability targets for your services.

0
0
SLA Percentage
%
Allowed Downtime
year
8.76 hrs
month
43.20 min
week
10.08 min
day
1.44 min
hour
3.6 sec
Downtime per year: 525.6000 minutes (0.10% of time)

Month = 30 days; year = 365 days.

Ninety-nine point nine percent uptime sounds close enough to perfect that it's easy to miss just how much downtime it actually allows, over eight hours a year, which only becomes obvious once that SLA percentage actually gets converted into real hours and minutes rather than left as an abstract number on a vendor's marketing page. This tool converts an SLA uptime percentage into actual downtime allowed per year, month, week, and day, turning a vague percentage into a concrete number worth comparing against an actual requirement.

See more about the Uptime Calculator

Useful for checking whether a cloud provider's SLA guarantee is actually good enough for a specific use case once it's converted into real hours, negotiating an SLA commitment by understanding exactly what a given percentage promises in practical terms, or setting an internal availability target and knowing exactly how much downtime margin that target actually leaves.

Key features

  • Clean interface
  • Fast processing
  • No signup required
  • Works offline

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Quick answers for Uptime Calculator

How precise is the downtime figure?
The highlighted period shows allowed downtime to 4 decimal places in minutes, while the grid cells switch to a rounded minutes or hours display depending on which is more readable for that period.
How do I set the SLA percentage?
A slider and a matching number input let you set anything from 90% to 99.999% uptime in steps of 0.001%, covering everything from a loose SLA down to "five nines".
What time periods does it break the downtime down into?
Tabs for year, month, week, day, and hour, and the calculator shows the allowed downtime for all five periods at once in a results grid rather than one at a time.
What is the calculation based on?
It multiplies the length of each period by (100% minus your chosen SLA percentage) to get the allowed downtime, the same math used to translate an SLA target into a concrete outage budget.