--- title: "MTTR Calculator" description: "Work out mean time to restoration for one asset from its failures and the hours each took to get back in service." --- [Back to Tools](/tools/) Tool # MTTR Calculator Work out mean time to restoration for one asset from its failures and the hours each took to get back in service. [Get Started Free](https://app.fixahead.com/signup) Example only. The starting values are invented: the pump in the worked example below. Failures restored Enter 0 or more The number of breakdowns repaired in the period, one for each completed breakdown work order on this asset. Do not count preventive or planned jobs. Restoration hours Enter 0 or more The hours from each breakdown until the asset was back in service, added together. In FixAhead, each one is the time from opened to completed on a breakdown work order. Restoration hours are not labor hours: enter elapsed hours. Two technicians on one 3-hour job make 3 hours, not 6. Enter hours; 90 minutes is 1.5. Enter one asset's figures. Pooling assets of different types gives a figure for none of them. Mean time to restoration 8 hours The average hours from a breakdown until the asset is back in service. Mean time to restoration 8 hours **MTTR (mean time to restoration)** is the expected time from a failure, or from its detection when the failure moment is unknown, until the asset is back in service. The figure is the average over an asset’s breakdowns. A lower figure means assets get back into service sooner. ## Formula MTTR = R ÷ N - **R** is restoration hours: the hours from each breakdown until the asset is back in service, added together. - **N** is the number of failures restored in the period. R includes the hands-on work and the waiting for people, parts, approvals and access. Hands-on time alone is a different, smaller measure: mean repair time. It is not MTTR. The [MTBF and MTTR guide](/blog/how-to-calculate-mtbf-mttr/) works through the method with a pump. [Maintenance metrics and KPIs](/guides/maintenance-metrics-and-kpis/) sets out when the restoration time starts. FixAhead reports MTTR per asset. See the [reporting features](/features/reporting/). ## Source IEC 60050-192, International Electrotechnical Vocabulary, Part 192: Dependability, on Electropedia. Entry 192-07-23 defines mean time to restoration as the expectation of the time to restoration, and deprecates “mean time to repair”. Entry 192-07-06 defines time to restoration from the instant of failure, or from its detection when that instant is unknown. Entries 192-07-19 and 192-07-21 define repair time and mean repair time, which exclude technical, administrative and logistic delays. ## Worked example Example only. The starting values are invented, and they are the same pump as the MTBF example. - Failures restored: 5 - Restoration hours: 40, the pump’s unplanned downtime, which included 14 hours of waiting for parts MTTR = 40 ÷ 5 = **8 hours** Of those 40 hours, 26 were hands-on repair. Hands-on time alone is mean repair time: 26 ÷ 5 = 5.2 hours. That is a different, smaller measure, not MTTR. ## Ready to get ahead of breakdowns? Start free. No credit card required. [Get Started Free](https://app.fixahead.com/signup) [Book a Demo](https://savvycal.com/fixahead/30-minutes-demo)