CPA (cost per acquisition)

CPA is spend divided by the number of conversions an ad platform reports for that spend. What counts as a conversion depends on how the account is set up.

Stock photos and example labels, not customers.

Definition

CPA is spend divided by the number of conversions an ad platform reports for that spend. What counts as a conversion depends on how the account is set up.

FormulaCPA = spend / conversions

Example with made-up numbers: An ad set spends 1,200 and the platform reports 30 purchases. CPA = 1,200 / 30 = 40.

How to use it

A conversion can be a purchase, a lead or any other event the platform tracks. Before comparing two CPAs, check that they use the same event and the same attribution window.

Platform CPA is useful inside a platform. Across platforms, prefer blended CAC, because platforms often claim the same customer.