Result
Churn rate
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This calculation is for informational purposes only and does not replace advice from a qualified professional. Formulas and rates may not fit your exact situation — double-check the figures before making decisions.
How it is calculated
Churn rate = customers lost ÷ customers at start of period × 100%. Retention rate = 100% − churn rate — the same information from the other side: what share of customers stayed.
The figure is measured over a specific period — a month, a quarter, a year — and monthly churn can't just be multiplied by 12 to get an annual figure: customers who left in different months would be different people, and the compounding effect of churn works out differently.
At a constant churn rate, average customer lifespan ≈ 1 ÷ churn rate (in the same period units as the churn rate itself) — for example, at 5% monthly churn, the average customer sticks around for about 20 months. That's an approximation assuming an equal chance of leaving at any point — in practice the risk of leaving is often higher in the first months, so this lifespan is worth checking against actual cohort data rather than relying on the formula alone.
The average lifespan from this calculator is the same figure used as "retention period" in the LTV calculation: the lower the churn, the longer a customer sticks around, and the higher their lifetime value.