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Downtime & Uptime Calculator

Uptime and downtime percentages, availability, and downtime cost — with the equivalent “nines”.

Enter values

Results update as you type.

Result

Uptime

99.0972%

Downtime
0.9028%
Downtime cost
$7,800.00
Downtime per year at this rate
79.1 hours

About the Downtime & Uptime Calculator

Uptime and downtime percentages, availability, and downtime cost — with the equivalent “nines”.

Also known as: uptime calculator, availability percentage, downtime cost, nines uptime.

How to use this calculator

  1. Enter period, downtime, cost per hour of downtime.
  2. The result updates instantly as you type — press Calculate (or Enter) at any time.
  3. Review the breakdown shown under the main result.
  4. Use Copy result or Share to save the answer or send a link with your inputs.

Formula

Uptime % = (period − downtime) ÷ period × 100

Worked example

Using the values pre-filled in the calculator above:

  • Period = 720 hours
  • Downtime = 6.5 hours
  • Cost per hour of downtime = 1,200

the calculator returns:

  • Uptime: 99.0972%
  • Downtime: 0.9028%
  • Downtime cost: 7,800
  • Downtime per year at this rate: 79.1 hours