Calculator
MTBF calculator
How long, on average, the equipment runs between one failure and the next. Enter the period, how long it was down due to failures and how many failures occurred.
Result
Fill in the fields to see the result.
Reference ranges are indicative and vary by industry, asset type and operating regime. Nothing you type leaves your browser.
How to calculate MTBF
Add up the hours the asset was supposed to run in the period, subtract the downtime hours caused by failures and divide by the number of failures. The result is the average operating time between one breakdown and the next.
Example: a pump ran 720 h in the month, was down for 18 h and failed 4 times. MTBF = (720 − 18) ÷ 4 = 175.5 h.
Common mistakes
Counting scheduled preventive work as a failure, mixing different assets in the same calculation and using calendar time instead of the hours the asset was actually supposed to run.
Full guide: How to calculate MTBF and MTTR.
Frequently asked questions
What is MTBF?
MTBF (Mean Time Between Failures) is the average operating time between two failures of a repairable asset. The higher it is, the more reliable the asset.
What is the MTBF formula?
MTBF = (period hours − downtime hours due to failure) ÷ number of failures in the period.
What is a good MTBF?
It depends on the asset type. The most useful comparison is the same asset over time and against identical assets: MTBF should go up.
Get notified at launch
Leave your email and tell us about your operation. A person will reply, not a bot.
