Churn Rate Calculator

Divide customers lost by customers at the start of the period to get the churn rate and its retention mirror.

About Churn Rate Calculator

The churn rate is the share of customers at period start that customers lost in the period represents, expressed as a percentage. The same figure is also shown per 1,000 and as a "one in every N" odds statement, which is easier to reason about when the rate is very small. Absolute counts hide scale — a rate normalises the number so you can compare periods, channels or cohorts of different sizes, where lower is better.

Formula

Churn Rate

Churn Rate = Customers lost in the period ÷ Customers at period start × 100

Customers lost in the period: The subset being measured
Customers at period start: The full population it is drawn from

Worked example

With the default values below, Churn Rate Calculator returns Churn Rate of 8.00%. Change any input above and every figure here is recalculated in your browser.

Inputs used

Customers lost in the periodminimum 0: 80
Customers at period startminimum 0: 1,000

Results

Churn Rate: 8.00%
Remaining (whole minus part): 920
Equivalent per 1,000: 80.0
One in Every: 12.5

Step by step

1Values used
2Churn Rate
3Churn Rate= 8.00
4Remaining (whole minus part)= 920
5Equivalent per 1,000= 80.0
6One in Every= 12.5

Assumptions and limits

The result is derived only from the 2 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation, tax or fees or charges into account.
Figures are rounded for display to 2 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
This is an estimate for general information and not professional financial, tax or legal advice. See the full disclaimer for the limits that apply to this kind of calculator.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Frequently Asked Questions

How is Churn Rate calculated?

Churn Rate = Customers lost in the period ÷ Customers at period start × 100 The churn rate is the share of customers at period start that customers lost in the period represents, expressed as a percentage. The same figure is also shown per 1,000 and as a "one in every N" odds statement, which is easier to reason about when the rate is very small.

Why does Churn Rate matter?

Absolute counts hide scale — a rate normalises the number so you can compare periods, channels or cohorts of different sizes, where lower is better.

What values do I need to enter?

This calculator takes 2 inputs: Customers lost in the period, Customers at period start. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.