What is a weekly active user (WAU)?
What is a weekly active user (WAU)?
Weekly active user, usually shortened to WAU, is a standard engagement metric in mobile measurement and product analytics. It counts how many distinct users were active in an app over the last seven days. Each user is counted once, regardless of how many sessions or events they generated during that period.
In addition to the seven day window itself, it is also important to clarify the definition of “active.” WAU is only valuable if the activity being counted reflects real use of the app. For one app, that may be an app open. For another, it may be a purchase, a session start, a completed level, a search, or another in-app event that signals meaningful engagement.
WAU is always calculated the same way, but what counts as an active user depends on the product. The event you choose to define “active” should reflect real usage, not just app opens.
How WAU is calculated
WAU is calculated by counting unique users who completed a defined action within a rolling seven-day period.
The calculation looks like this:
WAU = unique users active in the last 7 days
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When counting app opens as ‘active’, If one user opens the app 20 times in a week, that user still counts as one weekly active user. If another user opens the app once and completes the defined event, that user also counts as one.
For teams working in mobile analytics, this means WAU depends on two technical requirements. First, the app needs a reliable way to identify a user or device. Second, the business needs a clear event schema so the metric is tied to behavior that matters. Without those two pieces, WAU becomes inconsistent and hard to compare over time.
What counts as an active user?
An active user is any user who triggers the event used to calculate WAU within the seven-day window. That event is defined in your analytics setup. As stated above, it can be broad, such as an app open, or tied to a specific in-app action like a purchase, search, or completed level.
The choice depends on what you want WAU to represent. Using app opens gives a general view of usage. Using a more specific event narrows the metric to users who take a particular action.
There is no single correct definition. What matters is that the same event is used consistently so WAU can be compared over time and across campaigns.
WAU vs. DAU and MAU
WAU is one of three standard active user metrics, alongside daily active user (DAU) and monthly active user (MAU). The difference between them is the time window used.
- DAU: counts unique users in a single day
- WAU: counts unique users over 7 days
- MAU: counts unique users over 30 days
They are often used together to understand how often users return. DAU shows daily frequency. MAU shows overall reach. WAU sits between them and shows whether users come back within a short, repeatable timeframe.
Looking at the relationship between these metrics can often be more useful than looking at any one in isolation (this of course depends on your app business model and what you are measuring). For example, comparing WAU to MAU shows how many monthly users return within a week, while comparing DAU to WAU shows how often weekly users engage day to day.
Why MAU matters in mobile marketing
WAU is used to track short-term engagement. It shows how many users return within a seven-day window and is often used to check changes soon after they happen.
In practice, WAU is used to:
- Measure whether users come back within the first week after install
- Evaluate the immediate impact of campaign or product changes
- Compare engagement across different acquisition sources
WAU is interpreted as a trend. If it increases, more users are active within the weekly window. If it decreases, fewer users are returning. The metric does not explain why it changed. WAU needs to be read alongside install data and in-app events to understand what is driving the movement.
Turn WAU into a useful growth metric with Adjust
Adjust lets you define active users based on the events that matter to your app, then track WAU across campaigns, channels, and cohorts, all viewable in Datascape. This makes it possible to connect weekly engagement directly to acquisition quality and retention.
To see how WAU fits into a broader measurement strategy, and how Adjust can grow your app business in general, explore our analytics and attribution solutions or request a demo today.
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