Finance calculator
Churn Rate Calculator
This churn rate calculator works out the percentage of customers you lost over a period, your retention rate, and the average customer lifespan that churn implies. It measures customer (logo) churn; revenue churn can differ if you lose larger or smaller accounts.
How to use this calculator
- Enter the number of customers you had at the start of the period.
- Enter how many of those customers you lost during the period.
- Read your churn rate, retention rate, and the implied average customer lifespan.
Formula
- Churn rate = customers lost / customers at start x 100
- Retention rate = 100 - churn rate
- Average customer lifespan = 1 / churn rate (in the same period unit)
Example calculation
Losing 25 of 500 customers in a month is a 5% monthly churn rate, 95% retention, and an average customer lifespan of about 20 months.
How to interpret the results
- Good monthly churn for SMB SaaS is often around 3-5%; best-in-class B2B is well under 1% monthly.
- Average lifespan = 1 ÷ churn, so small churn improvements extend lifetime (and CLV) a lot.
- Track logo churn and revenue churn separately — losing a few large accounts hurts revenue more than the logo count suggests.
Frequently asked questions
What is a good churn rate?
For monthly SaaS, roughly 3-5% is common for SMB-focused products, while strong B2B/enterprise products are often under 1% per month. Lower is better.
How does churn relate to customer lifespan?
Average customer lifespan is approximately 1 ÷ churn rate. At 5% monthly churn, the average customer stays about 20 months (1 ÷ 0.05).
Is this customer churn or revenue churn?
This calculates customer (logo) churn — the share of customers lost. Revenue churn weights each customer by spend and can be higher or lower depending on which accounts leave.
Planning disclaimer
MoneyHackWise calculators are for general informational and planning purposes only and do not provide financial, investment, tax, legal, accounting, lending, or business advice. Results are estimates based on the inputs and assumptions shown.