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Customer Churn Calculator

Measure the share of a starting customer cohort lost during a period.

Use a consistent reporting periodCheck the calculation below

Your business figures

Runs on your device

METRIC SNAPSHOT

Your result

Let’s calculate.

Use the Calculate button to see your result.

Review the method below for assumptions and conventions.

How to use this tool

  1. Enter customers at period start, starting customers lost.
  2. Select Calculate to view the result.
  3. Check the method and assumptions below before using the result.

The method, explained

Customer churn rate = starting-cohort customers lost ÷ starting customers × 100.

A WORKED EXAMPLE

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.