Formulas used by this calculator
- CPA = included campaign cost ÷ conversions or attributed conversion credit
Worked example
Illustrative campaign cost of $1,500 produces 60 defined conversions. CPA is 1,500 ÷ 60 = $25.
If those 60 conversions are leads and only 12 become new customers, $25 remains the cost per lead. The media-only cost per new customer is $125, before other acquisition costs.
Choose the action that belongs in the denominator
Google Ads calculates cost per conversion from cost and conversion totals for the eligible reporting scope. Google Ads: interpreting conversion data.
For lead generation, decide whether the event is a raw form submission, valid inquiry, qualified lead, or completed sale. Use distinct labels in reporting. A campaign with a low submission CPA can still have an expensive cost per qualified opportunity.
Reconcile the cost definition
A media-only calculation should contain media cost. If the decision needs a fully loaded cost per action, include the relevant additional expenses consistently and document the allocation. Do not compare one campaign's fully loaded figure with another's media-only value.
Check currency, reporting dates, and conversion-window maturity. Recent spend can arrive before attributed outcomes. Saving the worksheet with the exact report scope makes it easier to distinguish a true efficiency change from a measurement mismatch.
Use actual CPA before setting a target
This tool describes the costs and outcomes entered. It does not tell an auction system what it can achieve, and it does not account for the value or margin of each conversion. A historical average should not become a bid target without checking economics and data quality.
Use the CAC calculator when the actual question is about first-time paying customers. Use allowable CAC when the question is what the business can afford. These are separate calculations, even when the same advertising report contributes some of the inputs.
Common questions
Is CPA the same as CPL?
Cost per lead is a CPA calculation whose action is a lead. Label whether the lead is raw, valid, or qualified. The formula is the same, but the cost and denominator must match the chosen event.
Should fractional conversions be rounded first?
Keep the attribution precision available in your source report. This tool accepts up to six decimals for conversion credit. Rounding the denominator to a whole customer can distort a low-volume campaign's cost per conversion.