Retention & Churn Rate Calculator

Why subtract new customers

If you just compared end-count to start-count, new signups would mask the customers you lost. Subtracting customers acquired during the period isolates the real question: of the people you already had, how many stayed?

Small retention gains compound

Because average lifetime is roughly the inverse of churn, improving retention is non-linear. Dropping monthly churn from 5% to 4% lifts implied lifetime from 20 to 25 months — a 25% jump from a one-point change.

See who churns, not just how many

A single rate tells you the size of the leak, not the cause. Cohort retention curves and per-user timelines show which users drop and when. Pug is open-source product analytics with retention cohorts and unified profiles built in.

Frequently asked questions

How do you calculate customer retention rate?

Retention rate = ((customers at end − new customers acquired during the period) ÷ customers at start) × 100. Subtracting new customers isolates how many existing customers you kept.

What is the difference between retention and churn?

They are two sides of one coin: churn rate = 100% − retention rate. If you retain 92% of customers in a month, your monthly churn is 8%.

How does churn relate to customer lifetime?

Average customer lifetime ≈ 1 ÷ churn rate (in the same period). 5% monthly churn implies an average lifetime of about 20 months. Lower churn compounds into much longer lifetimes.

Why does retention matter more than acquisition?

Retained customers cost nothing to re-acquire and compound revenue over time. A few points of retention improvement often outvalue a large increase in top-of-funnel traffic.