MTTR (Mean Time To Repair or Mean Time To Recovery) is the average time it takes to restore a system after a failure. It is calculated as total downtime divided by the number of incidents. Lower MTTR indicates faster incident response.

What is the difference between MTTR and MTBF?

MTTR measures recovery speed (time to fix a failure), while MTBF (Mean Time Between Failures) measures reliability (average time the system runs without failing). Together they determine availability: Availability = MTBF / (MTBF + MTTR).

What is a good MTTR target?

It depends on the system. Many teams target under 1 hour for critical services. High-availability systems often aim for under 15 minutes. The right target depends on your SLA, customer expectations, and the cost of downtime.

MTTF (Mean Time To Failure) is the average operating time before a non-repairable component fails. For repairable systems, MTBF is used instead. If you provide total uptime and incident count, this calculator shows the equivalent MTTF/MTBF figure.

How is availability calculated from MTTR and MTBF?

Availability = MTBF / (MTBF + MTTR). For example, if MTBF is 720 hours and MTTR is 1 hour, availability = 720 / 721 ≈ 99.86%. This maps directly to uptime percentage and nines (e.g., 99.9% = "three nines").

MTTR Calculator

Name: MTTR Calculator
Availability: InStock
Author: Nham Vu

Enter total downtime and number of incidents to calculate MTTR, plus explore related reliability metrics like MTTF, MTBF, and availability.

Incident Data

Total Downtime

Accumulated downtime across all incidents in the measurement period.

Number of Incidents

Total repair or recovery events in the same period.

Total Uptime (optional — for MTBF & availability)

Operating time without failures in the same period.

Enter your incident data and click Calculate.

Mean Time To Repair (MTTR)

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Downtime per Incident

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Same as MTTR

Total Incidents

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Repair events counted

Uptime Nines Reference

Level	Availability	Max downtime/year

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Summary

Enter total downtime and number of incidents to calculate MTTR, plus explore related reliability metrics like MTTF, MTBF, and availability.

How it works

Enter the total accumulated downtime across all incidents in a period.
Select the time unit (minutes, hours, or days) for the downtime value.
Enter the total number of incidents (repairs or recovery events) in that period.
Optionally enter total uptime to calculate MTBF and system availability.
MTTR is computed as total downtime divided by number of incidents.
Use the results to benchmark your incident response and reliability targets.

Use cases

Measure how quickly your on-call team resolves production incidents.
Track MTTR trends over sprints to evaluate reliability improvements.
Calculate system availability from MTTR and MTBF for SLA reporting.
Compare MTTR across services to identify the weakest reliability link.
Set data-driven recovery time objectives (RTO) for disaster recovery plans.
Report SRE error budget consumption during post-incident reviews.

Frequently Asked Questions

Last updated: 2026-06-11 · Reviewed by Nham Vu