Churn Rate Calculator
Calculate monthly and annualized customer churn rates and estimate the average customer lifespan.
Results
What is it?
Churn rate is the percentage of customers who stop doing business with you during a given period. It is the single most important metric for subscription businesses. A 5% monthly churn sounds small but compounds to ~46% annual churn — meaning nearly half your customers leave each year.
How to use
1. Enter the number of customers you had at the start of the period. 2. Enter how many customers you lost during that period. 3. Select the length of the measurement period. The calculator converts any period churn to a monthly rate, annualizes it using the compound formula, and estimates average customer lifespan.
Example scenario
A SaaS company starts the month with 1,000 customers and loses 50. Monthly churn = 5%. Annualized = 1 - (0.95)^12 = 46%. Average customer lifespan = 1/0.05 = 20 months. To sustain 1,000 customers, you must acquire 50 new ones every single month just to stay flat.
Pro tip
SaaS benchmarks: <2% monthly churn is excellent, 2–5% is acceptable, >5% is a red flag. Track revenue churn separately from customer churn — losing a $500/month customer hurts far more than losing a $10/month customer. Focus on "negative churn": expansions and upsells that offset losses. The fastest growth lever is cutting churn, not increasing acquisition.