CPA Calculator

CPA tells you how much it costs to acquire a customer or desired conversion. It is a key metric for Google Ads, Microsoft Ads, Reddit Ads, SEO, retargeting, and full-funnel lead generation. This calculator helps connect spend to actual outcomes.

What this calculator does

Calculate cost per acquisition using total spend and acquired customers or conversions.

How to use it

Enter media spend, management cost, and the number of acquisitions. Optionally include average customer value and margin to compare CPA with revenue and profit.

Formula and assumptions

• Media-only CPA = media spend ÷ acquisitions.
• Total CPA = (media spend + management cost) ÷ acquisitions.
• Profit after CPA = gross profit per customer − total CPA.

Assumptions

• Use customer acquisitions when possible; if using leads or conversions, label the metric clearly.
• Include management costs when evaluating business profitability.
• CPA should be compared against gross profit per customer, not just revenue.

Model details and limits

• Use the same period for spend and customer acquisitions. Media CPA excludes management; total CPA includes it. A zero acquisition count leaves CPA undefined even when money was spent.
• The profit comparison uses gross profit per customer, then subtracts total CPA. It excludes fixed overhead, taxes, returns and costs absent from the inputs. The CPA-to-value output is a percentage of revenue per customer.

Worked example

With $5,000 media spend, $1,500 management and 20 customers, media CPA is $250 and total CPA is $325. A $2,500 customer value at 50% gross margin yields $1,250 gross profit per customer, leaving $925 after total CPA. Total CPA is 13% of customer revenue.

Methodology references

• Google Ads average CPA definition

How to interpret your result

CPA should be evaluated against customer value and margin. A $300 CPA can be too high for one business and highly profitable for another.

Next steps

Lower acquisition cost