Engineering CalculationMTBF, MTTR and Availability Calculator
Track maintenance performance with MTBF, MTTR and availability, and combine equipment in series or parallel for system reliability.
Open the calculator →Formula
MTBF = operating time / number of failures
MTTR = total repair time / number of failures
Availability = MTBF / (MTBF + MTTR)
Worked example
708 h operating, 12 h repair, 4 failures in the month
MTBF = 177 h, MTTR = 3 h, Availability = 98.3 %
Where engineers use it
- Maintenance KPIs
- Critical equipment reviews
- Spares and standby planning
How to use
- Click Open the calculator. It runs free in your browser, on desktop or phone.
- Enter your values. Units and typical ranges are shown next to each input.
- Read the result and the step-by-step working, then print or add it to your Project BOQ.
Questions
Can it handle standby equipment?
Yes, use the series / parallel system reliability part of the tool.