Formula
(Total time - Downtime) / Total time x 100
How to measure
Track outage duration from monitoring tools and calculate the percentage of total time the service was available and functioning correctly.
Why track it
Uptime is a trust metric that directly affects retention and renewal for B2B products, where downtime disrupts a customer's own operations.
Example
A company maintains 99.95% uptime this quarter, meeting the service level agreement promised to enterprise customers.