Business calculators
Churn Rate Calculator
Find the share of customers lost and retained over a period. Your inputs stay in this browser.
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What this calculator measures
Churn rate measures the share of customers a business loses over a period. Retention rate is the complement — the share it keeps — and the two always add up to 100%.
Both metrics matter for subscription and recurring-revenue businesses, where retaining existing customers is often cheaper than acquiring new ones.
Formula
Inputs and variables
- Customers at start of period
- Enter the value used by this formula.
- Customers lost
- Enter the value used by this formula.
How to use the calculator
- Choose a display currency when money fields are present.
- Enter values that cover the same period, scope, and currency.
- Review the result, formula, and worked example before using the estimate in a decision.
- Change one assumption at a time to understand what drives the result.
Worked example
- 1A business starts the month with 500 customers and loses 25 of them.
- 2Churn rate is 25 / 500 x 100 = 5%. Retention rate is 100 - 5 = 95%, and 475 customers are retained.
How to interpret the result
Lower churn compounds — a small reduction in monthly churn meaningfully increases how long the average customer stays over a year.
Common mistakes and limits
- Mixing customer counts from different time periods, including customers who downgraded but did not cancel as churned, or comparing churn rates calculated over different period lengths.
Frequently asked questions
Is churn the same for every business?
No. Acceptable churn varies widely by industry, price point, and contract length.
Does this account for new customers gained during the period?
No. This is churn among customers present at the start of the period, not net customer growth.
How does churn relate to customer lifetime value?
Lower churn generally means a longer average customer lifespan, which increases lifetime value — see the customer lifetime value calculator.