CPA Calculator

Calculate cost per acquisition, required ad spend, or conversions. Choose the metric you need, then enter the other two campaign numbers.

Calculate

Ad spend

Total media spend for the period

Conversions

Purchases, leads, installs, or other actions

CPA

Average ad cost for each conversion

Calculated CPA Required ad spend Expected conversions

Conversions per 1,000 ad spend
Budget for 100 conversions

Enter values greater than zero

Both input metrics are required before the result can be calculated.

Currency changes the display symbol only. Enter every monetary value in the same currency.

How to calculate CPA, spend, and conversions

CPA connects campaign cost to results. Once you know any two values in the relationship, you can calculate the third without changing the conversion definition or reporting period.

Cost per acquisition: CPA = Ad spend ÷ Conversions
Required budget: Ad spend = CPA × Conversions
Expected results: Conversions = Ad spend ÷ CPA

Example

A campaign spends 2,500 and generates 100 purchases. Dividing 2,500 by 100 gives a CPA of 25. At the same efficiency, 200 purchases would require 5,000 in ad spend.

Research the ads behind the acquisition cost

Use Eachspy to compare long-running creatives, landing pages, advertisers, and spend signals before committing budget to a new angle.

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CPA calculator questions

What is CPA in advertising?

CPA means cost per acquisition or cost per action. It measures the average advertising cost required to generate one purchase, lead, registration, or other conversion you define.

How do you calculate CPA?

Divide total ad spend by the number of conversions. For example, 2,500 in ad spend divided by 100 purchases produces a CPA of 25.

Can this calculator solve for ad spend or conversions?

Yes. Choose the metric you want to calculate, then enter the other two. The calculator can solve for CPA, total ad spend, or the number of conversions.

What counts as a conversion?

Use the event your campaign is optimized around, such as a completed purchase, qualified lead, app install, or registration. Keep the conversion definition consistent when comparing campaigns.

What is a good CPA?

A good CPA is lower than the value or contribution margin generated by the conversion. There is no universal benchmark because margins, repeat purchases, and conversion quality vary by business.

What is the difference between CPA and CAC?

CPA usually measures campaign spend divided by a chosen action. Customer acquisition cost can include a broader set of sales and marketing costs required to acquire a new customer.

How do I set a target CPA?

Start with the contribution margin available before advertising. Your target CPA should stay below that break-even ceiling and leave room for the profit you want to earn per conversion.