Businesssaas

Retention Rate Calculator

Retention measured properly. New customers subtracted out, so growth cannot disguise churn.

Also called: customer retention calculator, retention percentage.

Retention rate

97%

97% of the starting cohort stayed. 3% left.

Churn rate

Customers retained

970

How this is calculated

Method and background

How this is calculated

Subtracting new acquisitions before dividing is the whole point. Ending with more customers than you started with says nothing about retention if acquisition covered the losses, and a headline that ignores this can show growth while the base is leaking.

retention = (end - new) / start * 100

S: Customers at the start
E: Customers at the end
N: New customers acquired

Worked examples

Each of these is asserted on every build. If a change to the engine ever moved one of these answers, the build would fail before the page could print it.

growth hiding 3% churn

Customers at the start: 1,000
Customers at the end: 1,050
New customers acquired in the period: 80

Retention rate97%

the base grew while 3% of it left

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perfect retention

Customers at the start: 500
Customers at the end: 500
New customers acquired in the period: 0

Retention rate100%

boundary

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everyone left

Customers at the start: 500
Customers at the end: 100
New customers acquired in the period: 100

Retention rate0%

boundary: every ending customer is new

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