Customer Churn Calculator
Calculate the proportion of a starting customer group lost during a reporting period.
How to use this calculator
- Enter the starting cohort and how many customers from that cohort were lost.
- Review the worked example for customer churn calculator and compare the inputs with your own units.
- Change one assumption at a time and recalculate if you need a second scenario.
Churn percentage
Churn rate = customers lost from starting cohort ÷ starting cohort × 100.
- This simple rate uses the start cohort as the denominator; revenue churn and time-weighted churn are different metrics.
- The result is calculated from the values entered; the page does not independently verify assumptions, data quality or real-world suitability.
Worked examples
A 500-customer cohort
A service loses 45 customers from a starting cohort of 500 during the measured period.
45 ÷ 500 × 100 = 9%
The period customer churn rate is 9%.
Understanding the result
A clearly defined churn event makes trends easier to compare between periods.
Customers may cancel and return, and a customer count does not describe the amount of revenue lost.
Important notes
Define cancellation, inactive accounts and period boundaries consistently.
Displayed figures are rounded for readability. Preserve more precision during intermediate calculations and verify the labels and units before using the estimate.
Frequently asked questions
What does the Customer Churn Calculator show?
A clearly defined churn event makes trends easier to compare between periods.
What assumptions should I check?
Define cancellation, inactive accounts and period boundaries consistently.
Does this replace expert or authoritative guidance?
Customers may cancel and return, and a customer count does not describe the amount of revenue lost.
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Related explanations
Learn the method behind the number or compare the terminology before using the calculator.
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This page provides a calculation tool plus explanatory information so you can understand what the result means and when the underlying method may not fit your situation.