Active users (DAU, WAU, MAU)
Accounts that performed a chosen action within a window: a day, a week or a month. The action and the window are choices, and both must be stated.
Formulaactive = did [action] within [window]
Try it · 30 seconds · from Atterna’s practice
Hi! Quick one — how many active buyers do we have? It’s for the monthly report.
| account type | rows |
|---|---|
| shoppers | 7,000 |
| sellers | 36 |
| staff | 40 |
| QA test | 60 |
The users table has 7,136 rows. What do you send Anna?
Preparing the practice…
How we work it through
- 1
Choose the action that matters for the decision: logged in, ordered, paid.
- 2
Choose the window and say it.
- 3
Exclude staff, test accounts and sellers before counting.
On the practice dataset
The query we run on Meridian, Atterna’s practice marketplace, and what it returns.
SELECT COUNT(DISTINCT buyer_id) FILTER (WHERE status = 'paid') AS paid,
COUNT(DISTINCT buyer_id) AS any_order
FROM meridian.orders;Result3,652 buyers paid, 3,705 placed any order, 7,000 are registered — three “active” counts
The common trap
Counting test accounts, staff or bots; mixing “logged in” and “bought”.
When an AI answers
“You have 7,136 active users.”
- What it didn’t know
- It counted every row in the users table, including sellers, staff and test accounts.
- Ask back
- “Which account types, which action and which window count as active?”
Read next
Examples use Meridian, Atterna’s fictional practice marketplace.