ClarityHow to use this tool
- Enter customers at period start, starting customers lost.
- Select Calculate to view the result.
- Check the method and assumptions below before using the result.
Input reference and sample values
Use the units and choices shown for each field. Sample values are provided for practice, not as recommendations.
| Input | Format and units | Sample |
|---|---|---|
| Customers at period start | Numeric value. Minimum: 1. | 1000 |
| Starting customers lost | Numeric value. Zero or positive. | 50 |
Result for these sample inputs
5 percent
- Starting customers retained
- 950
Select Try the example in the form to load these values and calculate them again. This replaces the current form inputs. Compare the result with the method and worked explanation below.
The method, explained
Customer churn rate = starting-cohort customers lost ÷ starting customers × 100.
Losing 50 from a starting cohort of 1,000 gives 5% churn and 950 retained starting customers.
What to keep in mind
Only losses from the starting cohort belong in the numerator. New-customer additions are excluded. Define active status and reactivations consistently.
Common questions
Can losses exceed the starting cohort?
Not under this definition. Such a count likely includes newly acquired customers or duplicate loss events.
Is this revenue churn?
No. Every customer counts once regardless of revenue. Revenue churn requires revenue-based inputs.
Methodology maintained by ClarityKit. How these tools are built and checked.