b2KIT

Churn Rate Calculator

Calculate customer and revenue churn rates with retention curves, cohort analysis, and impact on recurring revenue projections.

Tested tool guide Tested browser tools Checked August 16, 2026

What Churn Rate Calculator does and how it behaves

Churn can describe lost customers or lost recurring revenue, and this calculator keeps those views separate. It calculates both rates for a chosen period, displays retention curves and cohort comparisons, and shows how churn affects recurring revenue projections. The most common mistake is treating customer churn and revenue churn as interchangeable. They diverge whenever departing customers generate more or less revenue than the average retained customer. Entered customer and revenue figures remain in the browser rather than being uploaded.

How the result is produced

1

Customer and revenue rates

Customer churn relates customers lost during a period to the customers present at its start. Revenue churn relates recurring revenue lost to recurring revenue present at the start. Both calculations require matching period boundaries and populations. Closing customer count alone is insufficient when new customers joined during the same period because growth can conceal departures.

2

Cohorts and projections

Cohort analysis groups customers by a shared starting period and follows the proportion retained through later periods. A retention curve shows that surviving proportion by elapsed time, allowing cohorts from different dates to be compared. Recurring revenue projections carry the selected churn assumption into future periods, so they describe a scenario rather than a guaranteed forecast.

Good uses

  • A subscription finance team compares customer churn with recurring revenue churn to determine whether losses are concentrated among larger or smaller accounts.
  • A customer success manager compares signup cohorts to see whether newer groups retain customers longer than earlier groups at the same age.
  • A founder estimates how existing recurring revenue declines if the current churn assumption continues without replacement revenue from new customers.

Limits and checks

  • Use one consistent interval. A monthly numerator divided by an annual starting population does not produce a meaningful monthly or annual churn rate.
  • Confirm whether revenue churn is gross or net. Gross churn counts lost and contracted recurring revenue, while a net measure may offset those losses with expansion from retained customers.
  • Young cohorts have fewer completed periods than older cohorts. Their later retention values may be unavailable, so an apparently shorter curve does not necessarily indicate worse retention.

Common questions

Why can revenue churn exceed customer churn?

Revenue churn can be higher when the customers who leave contribute more recurring revenue than the average customer. It can be lower when departures are concentrated among smaller accounts. The rates answer different questions: customer churn measures account loss, while revenue churn measures the financial weight of lost recurring revenue.

Can I convert monthly churn to annual churn by multiplying by 12?

No, not when churn compounds across months. Under a constant monthly churn assumption, annual retention is the monthly retention rate raised to the twelfth power, and annual churn is one minus that result. Straight multiplication ignores the shrinking retained base and can overstate annual churn. The conversion also assumes the monthly rate remains constant.

References and verification

The behavioral notes were checked against the browser implementation. Standards and primary references below define the relevant format, formula, or platform behavior.

Related Tools