Mean Time To Restore Calculator

Work out mean time to restore instantly with clear inputs, formula shown and shareable results.

About Mean Time To Restore Calculator

Mean time to restore is total downtime divided by incident count, and it is one of the four DORA metrics. Separating detection from repair matters because they have different fixes: detection is monitoring and alerting, repair is runbooks, rollback automation and deployment speed. The DORA elite band is restoring service in under an hour.

Formula

MTTR and availability

MTTR = total downtime / incidents; repair time = MTTR - detection time; availability = 1 - downtime / period

Worked example

With the default values below, Mean Time To Restore Calculator returns Mean time to restore of 65.0. Change any input above and every figure here is recalculated in your browser.

Inputs used

Incidents in the periodminimum 1: 24
Total downtime across incidentsminimum 0 min: 1,560 min
Average time to detectminimum 0 min: 12 min
Period lengthminimum 1 days: 90 days

Results

Mean time to restore: 65.0 min
Repair time excluding detection: 53.0 min
Availability over the period: 98.7963%
DORA performance band: High - restores within a day

Step by step

1Values used
2MTTR and availability
3Mean time to restore= 65.0 min
4Repair time excluding detection= 53.0 min
5Availability over the period= 98.7963
6DORA performance band= High - restores within a day

Assumptions and limits

The result is derived only from the 4 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation, tax or fees or charges into account.
Figures are rounded for display to 4 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Frequently Asked Questions

Is the mean the right statistic?

It is skewed by one catastrophic outage. Report the median and a high percentile alongside it, since those describe the typical and worst experiences better.

What reduces MTTR fastest?

Automated rollback and the ability to deploy quickly. Teams that deploy in minutes can revert in minutes, which is why deployment frequency and MTTR correlate so strongly.