Marketing

CPA Calculator

Calculate cost per acquisition, back into your ad spend, or estimate how many conversions a target CPA supports.

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Enter the values above to calculate CPA.

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CPA Formula Explained

Calculate CPA

CPA = Ad Spend / Conversions

Calculate Spend

Ad Spend = CPA x Conversions

Calculate Conversions

Conversions = Ad Spend / CPA

What is CPA in advertising?

CPA measures how much it costs to produce one conversion, sale, or lead. It is one of the most practical metrics for performance marketing because it connects spend to a business outcome.

Marketers often use CPA targets to guide bidding, budget allocation, and channel comparisons. A campaign with a low CPC but weak conversion rate can still end up with a poor CPA, which is why CPA is more decision-ready than click metrics alone.

Frequently asked questions

What is CPA?
CPA stands for cost per acquisition. It tells you the average amount spent to generate one conversion, customer, or desired action from your advertising.
How do I calculate CPA?
Divide total ad spend by total conversions. If you spend $1,200 and get 30 conversions, your CPA is $40. You can also set a target CPA and work backwards to estimate required spend.
What is a good CPA?
A good CPA depends on your margins, average order value, and customer lifetime value. The right number is the one your business can profitably afford.
How does CPA relate to ROAS?
CPA measures cost per conversion while ROAS measures revenue per ad dollar. They are complementary: ROAS is easier to compute quickly, but CPA is more actionable because it connects directly to what you pay to generate a business outcome rather than just revenue.
What is the difference between CPA and CPL?
CPA (cost per acquisition) typically refers to the cost of generating a paying customer or completed conversion. CPL (cost per lead) measures cost per lead, which is an earlier-stage event. A lead that converts into a customer will have both a CPL and a downstream CPA.