Free online calculator
Customer Churn Rate Calculator
Measure the fraction of starting customers lost during a period. Includes a worked example, formula and practical FAQs.
Formula: Churn rate = customers lost ÷ customers at start × 100
How to use the Customer Churn Rate Calculator
Measure the fraction of starting customers lost during a period. Enter customers at the beginning and losses from that starting group.
Formula
Churn (%) = lost customers ÷ starting customers × 100; retention (%) = 100 − churn.
Worked example
Losing 15 of 300 starting customers gives 5% churn and 95% retention.
Interpretation and limitations
Starting customers must be positive; losses cannot exceed that base. Do not add newly acquired customers to the starting denominator. This tool measures customer churn, not revenue churn.
Customer Churn Rate questions
Does customer churn measure lost subscription revenue?
No. Customers may have different values. Revenue churn is a separate measure.
Can I multiply monthly churn by 12?
That is not an exact annual cohort loss. At constant 5% monthly churn, annual loss would be 1 − 0.95^12, approximately 45.96%.
Continue your calculation
For the next step, use the MRR Calculator or the Customer Lifetime Value Calculator. Review each tool’s input definitions before carrying a result into another calculation.
Frequently asked questions
Is this calculator free?
Yes. It runs in your browser and does not require an account.
How should I use the result?
Use the result as a planning estimate and verify business-critical decisions against your source records.