Custom Metric
01 Definition
Custom Metric meaning: A user-defined numeric measure you register to quantify something in reports.
A custom metric captures a number you want to measure, such as points earned, items previewed, or a custom score. In GA4 you register a numeric event parameter as a custom metric so it can be summed and reported. Metrics hold quantities, while dimensions hold descriptive labels.
Why it matters
How Custom Metric fits the work
Custom metrics let you track quantities unique to your business, so reports reflect the numbers that matter beyond standard counts like sessions and events.
In context
A game site registers a custom metric for points_earned, letting analysts sum total points across sessions and compare them by traffic source.
Practical note
GA4 limits custom metrics per property, and the parameter must contain valid numbers. Data appears only after registration, so define the metrics you need before you start collecting.