# CPA (cost per acquisition)

> CPA is what you spend on ads, on average, to get one conversion such as a purchase, signup or install.

Canonical: https://use-addy.site/glossary/cpa
Last updated: 2026-10-26

Also called: cost per action, cost per purchase, CAC

**Formula:** CPA = ad spend ÷ conversions

CPA is the number most businesses manage to, because it compares directly with what a customer is worth. The break-even CPA for a single purchase is your gross profit per order; anything above that loses money on the first sale unless customers come back.

## Related

- [ROAS vs CPA](https://use-addy.site/blog/roas-vs-cpa)
- [ROAS calculator](https://use-addy.site/tools/roas-calculator)
- [ROAS (return on ad spend)](https://use-addy.site/glossary/roas)
- [CPC (cost per click)](https://use-addy.site/glossary/cpc)
- [AOV (average order value)](https://use-addy.site/glossary/aov)