Skip to content
MTBF / MTTR CALCULATOR BY SYMESTIC

MTBF / MTTR Calculator

Use this MTBF / MTTR calculator to determine the mean time between failures (MTBF), mean time to repair (MTTR), availability and failure rate of your equipment – and see instantly where downtime costs you the most.

Guide FAQ
Display MTTR / MTTD
MTTR is often under an hour – switch to minutes if needed.
Reliability data
Observation period, failures and downtime – the basis for MTBF, MTTR and availability.
Observation period
hrs
Planned operating time, e.g. 700 h/month
Number of failures (breakdowns)
pcs
Unplanned failures within the period
Total downtime / repair time
hrs
Sum of all downtime caused by failures
Uptime 690hrs
Advanced & economics (optional)
Detection time for MTTD and downtime cost for the €-based assessment.
Total detection time
hrs
Optional – unlocks MTTD
Cost per hour of downtime
EUR
Margin / lost contribution margin per hour of downtime
Currency
! No uptime: the downtime meets or exceeds the observation period. MTBF and availability are 0 – please check your inputs.
AVAILABILITY
Rating

MTBF
hrs
MTTR
hrs
MTBF
hrs
Uptime ÷ failures · mean operating time between failures, higher = more reliable
MTTR
hrs
Mean repair time per failure · lower = faster
Failure rate
–/ 1,000 h
Failures per operating hour · = 1 / MTBF
MTTD
–hrs
Mean time to detect a failure
Breakdown of the observation period
How your planned operating time splits into actual production and downtime.
Uptime
Downtime / repair time
Cross-check: availability = MTBF / (MTBF + MTTR) = uptime / observation period (mathematically identical).
Values per observation period
Loss in the period
Savings per −1 hr MTTR
Savings per avoided failure
€
What is downtime costing you?
Enter the cost per hour of downtime on the left to see your loss and the €-levers per failure.
Availability rating
Public rating bands for inherent availability.
Needs improvement < 90 %
Average 90–95 %
Good 95–99 %
Excellent ≥ 99 %
Industry-specific MTBF/MTTR targets are only shown with verified platform data – we do not claim generic target figures.
Recommendations
Share & export your result
Your inputs are stored in the link – no account, no backend.
Request a live demo

Please enter the observation period, number of failures (≥ 1) and downtime to calculate MTBF, MTTR and availability.

A free tool from SYMESTIC – Manufacturing Execution System from the cloud.
HOW THE CALCULATOR WORKS

Quick guide: calculate MTBF & MTTR in 3 steps

From three inputs, the tool instantly calculates MTBF, MTTR, availability and failure rate. Here is how to proceed:

1

Capture the observation period

Enter the equipment's planned operating time for the period – e.g. 700 hours per month. Planned stops such as maintenance or changeovers do not count as downtime.

2

Enter failures & downtime

Record the number of unplanned breakdowns as well as the sum of the resulting repair and downtime.

3

Read & assess the result

MTBF, MTTR, availability and failure rate appear instantly. Optionally, detection time (MTTD) and downtime cost per hour reveal the €-loss and the biggest levers.

The formulas at a glance
MTBF Uptime ÷ failures Mean operating time between two failures of a repairable asset. Higher = more reliable.
MTTR Repair time ÷ failures Mean time to fix a failure. Lower = back in production faster.
Availability MTBF ÷ (MTBF + MTTR) Inherent availability – the share of time the equipment is operational.
Failure rate λ 1 ÷ MTBF Number of failures per operating hour, often shown per 1,000 hours.
MTTD Detection time ÷ failures Mean time to detect a failure – part of the total downtime.
All metrics consider unplanned failures only – planned maintenance and changeover times are deliberately left out so the values are not distorted.
FREQUENTLY ASKED QUESTIONS

MTBF, MTTR & availability – frequently asked questions

Terms, formulas and practical tips on the reliability of your equipment.