Uptime and downtime
Downtime Percentage Calculator
Enter downtime hours and total hours in the period to get downtime % for an asset, instantly.
Downtime % = Downtime hours ÷ Total hours in period × 100
Your numbers
Downtime %
Share of the period the asset was down
36 ÷ 720 × 100 = 5%
How the calculation works
Downtime % = downtime hours ÷ total hours in period × 100. It’s the share of the period a machine was stopped when it should have been running. Lower downtime % is better.
Use the hours the machine was scheduled to run as the period, not calendar hours. Otherwise a machine that runs one shift a day looks far better than it is.
The percentage tells you how much time you lost; reason codes tell you why. Split downtime by cause to see whether breakdowns, waiting for parts or changeovers take the biggest share.
This calculator is for one machine over one period, entered by hand. MachDatum CMMS tracks downtime per asset from breakdown work orders, so the hours are already recorded.
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Frequently asked questions
Downtime % = Downtime hours ÷ Total hours in period × 100. If a machine was down for 36 hours in a 720-hour period, downtime is 36 ÷ 720 × 100 = 5%.
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Tracking this metric by hand?
MachDatum CMMS calculates it for you. No spreadsheets, no manual tally.