Formula
Average effort rating across responses (typically 1-7 scale)
How to measure
Ask 'How much effort did you personally have to put forth to handle your request?' right after a task, then average the numeric responses.
Why track it
Lower effort scores correlate strongly with loyalty, making CES a leading indicator of churn risk tied to specific friction points.
Example
A billing self-serve change reduces average CES from 4.8 to 2.1 out of 7.