What Is Cost Per Acquisition (CPA)?
Cost Per Acquisition (CPA) is a key marketing metric that measures how much it costs to acquire a single customer or conversion through a paid campaign. A "conversion" can be a sale, a sign-up, a lead, or any goal you track. Knowing your CPA helps you judge whether a campaign is profitable and compare the efficiency of different channels.
How to Use This Calculator
Enter your total advertising spend for the period and the number of conversions that spend produced. The calculator divides spend by conversions to return the average cost of each acquisition. Use the same time window for both inputs (for example, one month) so the result is meaningful.
The Formula Explained
The formula is simple: $$\text{CPA} = \frac{\text{Total Ad Spend (\$)}}{\text{Number of Conversions}}$$ Total ad spend is everything you paid for the campaign, and conversions is the count of completed goals. A lower CPA means you are acquiring customers more cheaply.
Worked Example
Suppose you spent $5,000 on ads and generated 200 conversions. Your CPA is $$\$5{,}000 \div 200 = \$25$$ $25 per acquisition. If each customer is worth $80 in lifetime value, this campaign is comfortably profitable.
FAQ
What is a good CPA? It depends entirely on your margins. A good CPA is any value lower than the profit a customer brings you (their lifetime value).
Is CPA the same as CPC? No. CPC (cost per click) measures the cost of a click, while CPA measures the cost of an actual conversion, which is usually higher.
How can I lower my CPA? Improve targeting, refine ad creative, optimize landing pages, and pause underperforming campaigns to raise your conversion rate without raising spend.
