// definition

Churn Rate

Churn rate is the percentage of customers (or revenue) you lose over a given period, usually a month. If you start the month with 200 customers and 10 cancel, your monthly customer churn is 5%. Revenue churn measures the same thing in dollars and accounts for downgrades and upgrades.

Why it matters for developers

Churn quietly caps your growth: at 5% monthly churn, you replace your entire customer base every 20 months just to stay flat. Reducing churn compounds — it raises lifetime value and makes every acquisition dollar go further.