Why does the sum of daily unique users not match the monthly unique users?

In a monthly range each person is counted once, while in a sum of daily figures they are counted again on every day they visited. The gap between the two is itself a signal: the wider it is, the more often people came back.

How does unique user count differ from unique visitors in web analytics tools?

Web analytics tools usually count browsers and cookies, so the figure is closer to unique devices. In product analytics tools, when the product sends an account identifier, the basis moves closer to unique people and one person across several devices is counted once.

Unique User Count

Intermediate

Updated Jul 11, 2026 Shahin editorial 2 min read

PronunciationEN/juːˈniːk ˈjuːzər kaʊnt/

Unique user count is the number of distinct people who recorded at least one event within a time range, no matter how many times they returned.

The metric counts distinct identifiers rather than events. When the visitor is not signed in, that identifier belongs to a browser on one device, not to a person. The common mistake is treating unique users as additive: the sum of seven daily unique counts is almost always larger than the unique count for that week, because the same person is counted again on each day. One person arriving on a phone and on a laptop also appears as two unique users until the two identities are stitched together.

How it is calculated

Unique user count = number of distinct user identifiers in the selected time range

The identifier is the user ID when the visitor is signed in and the anonymous device identifier otherwise. The unit is people, and the time range is part of the metric definition rather than a filter applied afterwards; changing the range recomputes the number and it cannot be derived by summing shorter ranges.

FAQ

Sources:GA4 — Users metric