MTTR

A DORA stability metric. Clarify whether the clock stops at mitigation or full recovery.

MTTR = sum of restore durations ÷ number of incidents.

Tip: Keep “Total Restore Time” and “Incidents” on the same basis (units, period, and definition) before you calculate.

Cluster: DevOps hub · Software Testing hub · Percentage guide

MTTR (mean time to restore/recover) is average time to restore service after an incident.

Enter total restore time (same unit for all) and incident count.

Sum of restore durations (e.g. minutes)
Number of incidents in the sample

Mean Time to Restore

Understanding MTTR

How we calculate. MTTR = sum of restore durations ÷ number of incidents. See our methodology and accuracy policy .

Real-world scenario: A typical MTTR case uses total restore time 250 and incidents 5. Enter the same figures below to reproduce the worked path.

What is MTTR?

A DORA stability metric. Clarify whether the clock stops at mitigation or full recovery.

  • Use one time unit (minutes recommended)
  • Count customer-impacting incidents
  • Document start/stop events

The Formula

Mean Time to Restore
MTTR = Total restore time ÷ Incidents

Worked Example

Scenario: 5 incidents totaling 250 minutes to restore.
Step 1: Total time = 250
Step 2: Incidents = 5
Step 3: MTTR = 250 ÷ 5 = 50 minutes
Answer: MTTR is 50 minutes.

Common Use Cases

  • SRE reviews: recovery speed
  • On-call health: weekend vs weekday
  • SLO programs: error-budget burn context

Pro Tips

  • Exclude planned maintenance if policy says so
  • Track MTTD separately
  • Improve runbooks when MTTR spikes
ScenarioWhen to use
Percent of a numberFinding a part of a whole (tax, tip, score)
Percent changeComparing old vs new values

Limitations: MTTR results are educational DevOps/FinOps planning aids—not SLAs or billing guarantees. Confirm definitions with your platform and finance policies.

Common mistakes

  • Swapping part and whole: The denominator must be the full total, not a subset.
  • Rounding too early: Carry extra decimal places through multi-step work before rounding the final percent.
  • Mixing percent and decimal forms: Enter rates in the format the calculator labels expect.

The worked example for mttr calculator was verified with the calculator form on this page—enter the same values to confirm the result.

When to use this calculator

  • Use this page when your wording matches mttr calculator and the form labels on screen.
  • Use percent of a number for “what is X% of Y?” problems.
  • Use number is what percent when you know part and whole and need the percent.

Still unsure about mttr calculator? Start with the quick answer above, then open the linked calculator that matches your wording.

Frequently Asked Questions

How do I use this mttr calculator calculator?

For mttr calculator, enter the values labeled on the form, then press Calculate. Compare the result to the worked example on this page.

What formula does this page use?

See the quick answer and formula box above for mttr calculator—the same percentage calculator expression is applied to your inputs.

What if my result looks wrong?

When checking mttr calculator, re-check part vs whole (or rate vs base), rounding, and whether percents were entered as 25 rather than 0.25 when the form expects percents.

Authoritative References

For DORA and FinOps definitions, consult: