Marketing calculators
CPA Calculator
Calculate the average ad spend per conversion, and per lead, for a campaign. Your inputs stay in this browser.
Live calculator
Enter your numbers
What this calculator measures
Cost per acquisition (CPA) divides ad spend by the number of conversions a campaign produced, showing what each customer or signup cost to acquire through that spend.
CPA is usually measured per campaign or per channel — it is a narrower, more immediate view than customer acquisition cost (CAC), which typically blends all sales and marketing spend across the whole business.
Formula
Inputs and variables
- Ad spend
- Enter the money amount used by this formula.
- Conversions (sales or signups)
- Enter the value used by this formula.
- Leads generated
- Only needed if you track leads separately from conversions. This input is optional.
How to use the calculator
- Choose a display currency when money fields are present.
- Enter values that cover the same period, scope, and currency.
- Review the result, formula, and worked example before using the estimate in a decision.
- Change one assumption at a time to understand what drives the result.
Worked example
- 1A campaign spends $5,000 and generates 100 conversions and 400 leads.
- 2CPA is $5,000 / 100 = $50 per conversion. CPL is $5,000 / 400 = $12.50 per lead.
How to interpret the result
Comparing CPA across channels or campaigns shows which ones are acquiring customers most efficiently for the same spend.
Common mistakes and limits
- Comparing CPA across channels with different attribution windows, ignoring conversions that happen after the tracked click, or treating campaign-level CPA as the same figure as company-wide CAC.
Frequently asked questions
Is CPA the same as CAC?
They use the same division, but CPA is usually one campaign's ad spend over its conversions, while CAC usually blends all sales and marketing cost across the business. See the customer acquisition cost calculator for the broader version.
Do I need to enter leads?
No, it is optional. Enter it only if you track leads separately from final conversions.
What counts as a conversion?
Whatever your campaign is optimizing for — a sale, a signup, or another defined action. Keep it consistent when comparing campaigns.