When to use this calculator
A clearly defined starting cohort avoids confusing customer losses with new customer acquisition.
Explore the marketing & customer calculators for other questions in this topic. For a related calculation, use the Customer Lifetime Value Calculator: Estimate customer lifetime gross profit from order behaviour and an entered duration.
PUTTING IT INTO PRACTICE
Customer Churn Rate: a worked example
The values below are an illustrative example, not a recommendation. Replace them with measurements or assumptions that match your question.
| Input | Example value |
|---|---|
| Customers lost (integer) | 20 |
| Customers at period start (integer) | 400 |
| Result | 5 % |
- Check the input labels and enter the example values above.
- Apply the relationship: Churn (%) = customers lost/starting customers × 100.
- The result is 5 %, rounded for display.
How to interpret your result
Use a fixed cohort and the same reporting period; this is customer churn, not revenue churn.
Define the event, audience and attribution window before calculating a rate. Clicks, customers and orders are different units. Acquisition cost and campaign CPA may cover different spending categories.
Frequently asked questions
Should I count unique users or total events?
Use the definition matching your metric. State it consistently because repeat events can produce a different rate from unique people.
When is the customer churn rate calculator useful?
A clearly defined starting cohort avoids confusing customer losses with new customer acquisition.
How do I use the customer churn rate calculator?
Enter customers lost (integer), customers at period start (integer). The result updates automatically. Use the units shown beside each input; the example values illustrate the method.
Which formula does this calculator use?
Churn (%) = customers lost/starting customers × 100.
What should I check before using the result?
Use a fixed cohort and the same reporting period; this is customer churn, not revenue churn.
How are results rounded?
Scalar numbers display up to six decimal places, with scientific notation for very large or small values. Text, fraction, date and schedule outputs use the format described on the tool. Intermediate calculations use JavaScript floating-point arithmetic. Keep sensible precision for your measurements.
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