Retention rate calculator
Retention rate is the share of one group of users — a cohort — who came back after a given number of days. The group is fixed on the day they first used the app, so the denominator never changes as you look further out.
Enter both numbers to see a result.
This calculator runs entirely in your browser. Nothing you type is sent to a server or stored.
Read a retention result in context
The percentage answers one narrow question: what share of this starting cohort returned at the chosen interval. It does not explain why they returned or whether users acquired later behave the same way.
Cohort size: 200 Returned on D7: 42 D7 retention: 42 ÷ 200 × 100 = 21%
How it is calculated
Retention rate = returned users ÷ cohort size × 100
When to use it
Use it when you have counted a cohort by hand — from a GA4 export, a launch week, or a single campaign — and want the percentage without building a report. For ongoing measurement, read retention from Analytics rather than recalculating it each time.
What to watch out for
- A small cohort produces percentages that swing on one or two people — always look at the cohort size next to the rate
- Returned users cannot exceed the cohort; if yours does, the two numbers are measuring different groups
- D1, D7 and D30 are each measured against the original cohort, not against the previous day
Frequently asked questions
Can I use this for D1, D7 and D30 retention?
Yes. Use the original cohort size as the denominator and enter the users who returned at the interval you are measuring.
Why does the calculator show a range?
The range shows sampling uncertainty. A rate measured from a small cohort can move substantially when only a few users behave differently.
Should returned users ever exceed the cohort size?
No. If they do, the counts use different populations or one value counts events rather than distinct users.