CPA Calculator
Cost per acquisition: CPA = ad cost ÷ conversions. $1,800 for 45 conversions is a $40 CPA.
Google Ads: Cost
Google Ads: Conversions
CPA = $1,800 ÷ 45 = $40.00
Next: the ROAS that matches your break-even CPA → Break-even ROAS calculator
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Get my auditHow to calculate CPA
CPA = CPC ÷ conversion rate
Cost per acquisition is what you pay in ad spend for each conversion. For the definition, see our glossary entry on CPA.
| Step | Example | Where to find it |
|---|---|---|
| Ad cost | $1,800 | Google Ads: Cost |
| Conversions | 45 | Google Ads: Conversions |
| CPA | 1,800 ÷ 45 = $40 | Google Ads: Cost / conv. |
| Same, from CPC | $1.50 ÷ 3.75% = $40 | Avg. CPC ÷ Conv. rate |
Break-even CPA: the most you can pay
A CPA only means something next to what a sale earns. Break-even CPA is order value × contribution margin: an $80 order at a 40% margin leaves $32 to spend on winning it. Above that, each sale loses money. The “Break-even” mode above works it out, and the break-even ROAS calculator shows the same line as a ROAS, with a profit cushion on top.
When you hand bidding to Google, the goal you set is a target CPA, covered in our glossary entry on target CPA (tCPA). Set it below break-even so each conversion leaves profit. If your CPA is running high, see how to lower a high CPA.
CPA questions
How do you calculate CPA?
Divide ad cost by conversions. $1,800 for 45 conversions is a $40 cost per acquisition. You get the same answer from CPC ÷ conversion rate: $1.50 ÷ 3.75% = $40.
What is a break-even CPA?
The most you can pay for a sale before it loses money: order value × contribution margin. An $80 order at a 40% margin can afford $32 in ad cost; pay more and every sale loses money.
How is CPA different from target CPA?
CPA is what you actually paid per conversion. Target CPA is the goal you give Google's automated bidding. Set the target below your break-even CPA so there is profit left over.
How do I lower a high CPA?
Raise the conversion rate or lower the cost per click: CPA = CPC ÷ conversion rate, so either one moves it. Conversion rate is usually the bigger lever. Our workflow on lowering a high CPA goes step by step.
Built by the iClick team · Reviewed by Eric Mascarenhas, Founder & Lead Strategist · Updated
