How it works
Dn retention = original users active in the Dn window ÷ original cohort size × 100.
Retention and conversion
Cohort retention calculator
Calculate point-in-time cohort retention: how many original users returned on your selected day or window.
- D7 retention
- 30%
- Original users inactive in window
- 700
This is point-in-time retention, not rolling retention. Do not mix new users, different windows, or different activity events.
Worked example
300 original users active on D7 from a cohort of 1,000 represent 30% D7 retention.
Assumptions and limits
This is point-in-time retention, not rolling retention. Do not mix new users, different windows, or different activity events.
Frequently asked questions
How do I use the cohort retention calculator?
Calculate point-in-time cohort retention: how many original users returned on your selected day or window.
What counts as active?
Define a product value event and window before analysis; do not change the definition between cohorts.
Do I need an account and are my inputs uploaded?
No account is required. Calculations run in your browser. Entered numbers and text are not included in tool analytics events; only the tool ID, language, and action are recorded.
Want to go past the numbers and see the real market?
Noctral shows estimated MRR, live ads, creators, and competitors so you can validate opportunities with real signals instead of projections.
See Noctral data
