GA4 bounce rate: what it is and how to calculate it

In GA4, bounce rate is the share of sessions that were not classified as engaged sessions. Calculate it by dividing non-engaged sessions by all sessions in the same report and segment.

Bounce rate = non-engaged sessions ÷ total sessions × 100.

In this fictional example, a report contains 800 sessions, with 520 engaged and 280 not engaged, the calculation is:

280 ÷ 800 × 100 = 35%.

That 35% describes the example’s segment and period; by itself, it does not tell you whether the page did its job.

What GA4 counts as an engaged session

GA4 classifies a session as engaged if it meets at least one of these criteria: it lasts longer than the configured timer, includes a key event, or has two or more page or screen views. The timer is 10 seconds by default, but you can change it in Google tag settings. GA4 Help defines both metrics and their criteria; Google’s setup instructions explain how to adjust the timer.

There is an important exception: first_visit, first_open, and session_start are excluded from engaged-session calculations even if they are marked as key events. So do not assume that every marked event makes a session engaged. When comparing weeks or pages, check that the timer and event setup were consistent.

It is different from the old formula and from conversion rate

GA4 bounce rate is the complement of engagement rate: for the same property, segment, and period, if engagement rate is 65%, bounce rate is 35%. This is not the old Universal Analytics definition based on single-page sessions with no further recorded interaction. It is also not a conversion rate, which measures the share that completed a defined action. A social media conversion rate uses a chosen event and base to answer a different question.

A short page can answer a query without meeting GA4’s engagement criteria. Bounce rate alone does not prove that the visit was useless or that the page is failing.

Where to find bounce rate

Most standard GA4 reports do not show this metric by default. An Editor or Administrator can add it to a detail report, such as “Pages and screens,” through report customization. If you do not have that role or you are viewing an overview report, the option to add metrics may not appear. Google’s GA4 Help walks through those steps.

When reading the result, segment by landing page or session source and medium, then compare it with the page’s purpose. If one segment changes unexpectedly, also check that pages are tagged and key events represent real actions. The metric can show where to look; it does not identify the cause by itself.

Conceptual cover generated with AI.