Annualized Churn Rate
Annualized churn estimates the yearly customer loss implied by a constant monthly churn rate.
Annualized churn converts a monthly churn assumption into the cumulative loss from an opening customer group over twelve months. The calculation compounds retention: each month’s churn applies to the customers remaining, rather than repeatedly to the original count.
Example
If monthly customer churn stays at 2%, monthly retention is 98%. After twelve months, expected retention is 0.98 to the twelfth power, about 78.5%. Estimated annual churn is therefore about 21.5%, rather than 24%.
How to use it
Use the conversion to understand how modest-looking monthly losses accumulate. For the example company, compare the estimate with actual twelve-month cohort retention. If they diverge, investigate customer age and renewal timing rather than forcing the observed data into a constant-rate assumption.
This is a model, not an observed annual retention result. It assumes a constant rate and a fixed customer group, with no reactivation. Annual contracts, seasonal renewals, and age-dependent churn often make the assumption inappropriate. Use c as a decimal: 2% means 0.02.
Further reading: David Skok on Annualized Churn Rate.
Related: Customer churn rate, Cohort retention.