Churn Rate Calculator

Calculate customer churn and retention over a period.

Customers at the start	1,000
Customers lost during the period	45
New customers during the period	80

Customers at the start

Customers lost during the period

New customers during the period

Churn rate

4.5%

Retention 95.5%. Ending customers 1,035. If this is monthly, yearly churn compounds to 42.5%.

Customers lost

4.5 customers lost in every 100About 1 in 22 of the customers you started with

Customers over the period

Starting customers1,000
Lost−45
Added+80
Ending customers1,035

About the Churn Rate Calculator

Enter the customers at the start of the period, how many left and how many joined. The calculator gives the churn rate, the retention rate, the ending customer count and, if the period is a month, the churn compounded over a year.

Churn rate is the share of customers at the start of a period who left during it. New customers don't reduce churn; they're counted separately. Monthly churn compounds: 3% a month is about 31% a year.

The formula

Churn = customers lost ÷ customers at start; yearly = 1 − (1 − monthly)¹²

Worked example

1,000 customers at the start of a month; 45 left and 80 joined

Churn: 45 ÷ 1,000 = 4.5%; retention 95.5%
Ending customers: 1,000 − 45 + 80 = 1,035
4.5% a month compounds to 42.5% a year

Questions people ask

What's revenue churn?

Lost recurring revenue ÷ starting revenue; with upsells it can be negative (net expansion).

What's good churn?

For B2B SaaS, under 1% monthly is strong; consumer apps are typically much higher.

How does churn set customer lifetime?

Average lifetime is 1 ÷ churn: 4.5% a month means about 22 months.