Last Updated: December 30, 2024

Here is how you can calculate ‘New’ and ‘Returning users in GA4 BigQuery.

First thing first. 

Both ‘New’ and ‘Returning’ users metrics need to be manually calculated. 

They are not available as default fields in the GA4 BigQuery export schema.

Here is how most people calculate new and returning users in GA4 BigQuery:

If the value of ‘ga_session_number’ event parameter is 1, classify the user as a ‘New User’.

If the value of ‘ga_session_number’ event parameter is greater than 1, classify the user as a ‘Returning User’.

However, since we have now established that any event (like ‘user_engagement’, ‘scroll’, or custom_event) in GA4 can start a new session, this definition of new and returning users is no longer valid.

This is because ‘ga_session_number’ is no longer a reliable indicator of user status.

‘ga_session_number’ is not a reliable indicator of user status.

‘ga_session_number’ tells you which session an event belongs to (1 = first session, 2 = second session, etc.).

If any event is fired before ‘session_start’, it may not have the necessary context (like ‘ga_session_number’) when processed.

For example, if the first event is not ‘session_start’ but something like ‘user_engagement’, then ‘ga_session_number’ might not even be set in that event.

Once GA4 “catches up” (i.e., ‘session_start’ fires later), all subsequent events in the session get assigned ‘ga_session_number = 1’, but the first event may still miss the session context, so ‘ga_session_number’ will be NULL for that event.

‘ga_session_number > 1’ doesn’t always mean “Returning User” because a user can have multiple sessions for the same visit.

For example:

User is inactive for 30+ min, new session starts (Session timeout) → Does ‘ga_session_number’ increase? Yes (Session 1 → 2) → Is it a “Returning User”? No, same user, same visit.

Slow website delays ‘session_start’ event (Tag-firing delay) → Does ‘ga_session_number’ increase? Yes (Session 1 → 2) → Is it a “Returning User”? No, same user, same visit.

User gives consent, new session starts (Consent Mode) → Does ‘ga_session_number’ increase? Yes (Session 1 → 2) → Is it a “Returning User”? No, same user, same visit.

Following is a significantly more accurate logic for calculating new and returning users.

Calculate the values of the ‘New Users’ by counting the distinct ‘user_pseudo_id’ where the ‘event_date’ of the user’s first event (within the specified time range) of the day matches their ‘first interaction date’ (derived from ‘user_first_touch_timestamp’ field). Only consider the user’s first event per day, not every event.

Calculate the values of the ‘Returning Users’ by counting distinct ‘user_pseudo_id’ where the ‘event_date’ of the user’s first event (within the specified time range) is after the user’s first interaction date. Only consider the user’s first event per day, not every event.

To calculate first time users, check out this article: Learn to Track First Time Users in GA4 BigQuery.