Retention Rate Calculator

Work out what share of customers stay across a period, and the churn that is its mirror image.

About Retention Rate Calculator

The retention rate is the share of customers at period start that customers retained at period end 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 higher is better.

Formula

Retention Rate

Retention Rate = Customers retained at period end ÷ Customers at period start × 100

Customers retained at period end: The subset being measured
Customers at period start: The full population it is drawn from

Worked example

With the default values below, Retention Rate Calculator returns Retention Rate of 92.00%. Change any input above and every figure here is recalculated in your browser.

Inputs used

Customers retained at period endminimum 0: 920
Customers at period startminimum 0: 1,000

Results

Retention Rate: 92.00%
Remaining (whole minus part): 80
Equivalent per 1,000: 920.0
One in Every: 1.1

Step by step

1Values used
2Retention Rate
3Retention Rate= 92.00
4Remaining (whole minus part)= 80
5Equivalent per 1,000= 920.0
6One in Every= 1.1

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 Retention Rate calculated?

Retention Rate = Customers retained at period end ÷ Customers at period start × 100 The retention rate is the share of customers at period start that customers retained at period end 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 Retention Rate matter?

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

What values do I need to enter?

This calculator takes 2 inputs: Customers retained at period end, 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.