MTBF / MTTR Calculator
Calculate Mean Time Between Failures, Mean Time to Recovery, and system availability from your operational data.
MTBF
9.9 days
Your system fails roughly once every 9.9 days
MTTR
2.0 hours
It takes an average of 2.0 hours to recover
Availability
99.1667%
Two nines territory
Where you fall on the nines scale
Understanding MTBF and MTTR
MTBF (Mean Time Between Failures) measures how long your system typically runs before something breaks. A higher MTBF means fewer outages. Formula: (total operational time - total repair time) / number of failures.
MTTR (Mean Time to Recovery) measures how long it takes to get back up and running after a failure. A lower MTTR means faster recovery. Formula: total repair time / number of failures.
Availability combines both metrics into a single percentage: MTBF / (MTBF + MTTR) × 100.
Why MTTR Matters More Than MTBF
You cannot prevent all failures. Hardware fails, software has bugs, networks go down, and third-party services have outages. What you can control is how fast you detect and recover from those failures.
Improving your MTTR from 4 hours to 30 minutes has a bigger practical impact than doubling your MTBF. The key to reducing MTTR is detection speed — if monitoring alerts you within a minute of downtime starting, you can begin recovery immediately instead of discovering the problem hours later when a customer calls.
The four stages of recovery are: detection (knowing something is wrong), diagnosis (figuring out what broke), repair (fixing it), and verification (confirming it is actually fixed). Monitoring directly improves the first stage, and often helps with the second by providing logs and status data.
Track your MTBF and MTTR automatically
Uptime Monitor checks your sites every minute and gives you the data to calculate real reliability metrics. Free for up to 3 sites.