Customer Cohort Retention Calculator
What share of starting customers remained at the end of a measurement window? Check the formula, a worked example and the stated measurement limits.
Result for the values shown.
Calculations run in your browser.
What to enter
| Input | Meaning and units |
|---|---|
| Starting customers (customers) | Enter a whole count in customers; keep the reporting population consistent. |
| Starting customers lost (customers) | Enter a whole count in customers; keep the reporting population consistent. |
Understanding your result
Use a cohort comparison to distinguish acquisition from retention. Report customer counts alongside percentages to reveal how small cohorts influence the result.
Common mistakes
- Adding new customers to retained starting customers changes the metric.
- Monthly and annual retention windows are not directly interchangeable.
Check your calculation
- Use the worked example as a known reference case, then change one input at a time and check the direction and units of the response.
Choose a consistent measurement basis
Follow one starting cohort over an explicit period and define the retained event. Customers acquired later are excluded; cancellation, inactivity and renewal can be different retention definitions.
A second independently worked case
No losses from a 100-customer starting cohort give 100% retention. Inputs: Starting customers: 100 customers; Starting customers lost: 0 customers. Results: Customer retention: 100 %; Customer churn: 0 %; Retained starting customers: 100 customers.
Precision and output units
Displayed results: Customer retention in %, rounded to 2 decimal places; Customer churn in %, rounded to 2 decimal places; Retained starting customers in customers, rounded to 0 decimal places. Display rounding does not establish the precision of the original measurements or estimates. A small positive rate can round to 0.00%; inspect the underlying counts before treating displayed zero as an absence of events.
Calculation checks, sources and review limits
What share of starting customers remained at the end of a measurement window?
What share of starting customers remained at the end of a measurement window? Check the formula, a worked example and the stated measurement limits.
Common uses
- What share of starting customers remained at the end of a measurement window
- Compare Customer Cohort Retention across scenarios under matching definitions.
How it works
Subtract lost customers from the starting cohort. Divide retained and lost counts separately by the starting count. Under this simple convention the two percentages add to 100%.
Worked example
500 − 40 = 460 retained; 460 ÷ 500 = 92%, and churn is 8%. Enter starting customers 500 customers, starting customers lost 40 customers. The independently worked result is customer retention 92 %; customer churn 8 %; retained starting customers 460 customers. Compare this example with your reporting definitions before substituting your own figures.
FAQ
Can customer and revenue retention move differently?
Yes. Losing several small accounts while retained large accounts expand can reduce customer retention while increasing net revenue retention. The metrics weight different quantities.
Does retention mean daily activity?
Only if activity is the declared retained event. A paid renewal, active contract and product-use event can each define different cohorts and retention rules.