Formula
Active seats used / Seats purchased x 100
How to measure
Divide the count of seats with recent login or activity by the total number of seats a customer has purchased.
Why track it
Low seat utilization is both a churn risk, since unused seats look like wasted spend to a buyer, and an upsell opportunity if utilization is actually high.
Example
An account purchasing 50 seats but only actively using 30 has a 60% seat utilization rate, flagging renewal risk.