Cost Per Acquisition Calculator
Work out your CPA from total spend and conversions, then see how many conversions a budget can buy.
Runs entirely in your browser. Your numbers are never uploaded anywhere.
How to use this tool
This CPA calculator works in two directions. To find your cost per acquisition, stay on the first tab, enter your total marketing spend for a period and the number of conversions that spend produced, then press Calculate CPA. A conversion can be a paying customer, a signup, or a qualified lead, depending on how you define success. To plan ahead instead, switch to the second tab, enter the budget you have available and the target CPA you are willing to pay, and the tool tells you roughly how many conversions that budget should buy.
The formula
Cost per acquisition, also called customer acquisition cost or marketing spend per customer, is simply the money you spent divided by the results it generated. If you measure leads rather than sales, the same math gives you a lead cost. The planning side of the tool flips the formula around: Conversions = Budget / Target CPA, which estimates how many results a given budget can afford at the price you set.
A real example
Suppose a campaign spent $5,000 across ads, tools, and creative, and brought in 125 new customers. The CPA is 5000 / 125 = $40.00 per customer. Now imagine next quarter you have a $10,000 budget and you want to keep paying around $40 per customer. Dividing 10000 by 40 gives 250, so that budget should buy roughly 250 conversions if your efficiency holds.
Common questions
What is a good cost per acquisition?
There is no single benchmark. A healthy CPA is one that stays comfortably below the lifetime value of the customer it brings in. A subscription product earning $400 per customer can absorb a much higher CPA than a one-time $20 sale.
Is CPA the same as customer acquisition cost?
They are used interchangeably most of the time. Both measure marketing spend per customer. Some teams reserve customer acquisition cost for a fully loaded figure that also includes salaries and overhead, while CPA often refers to a single channel or campaign.
Can I use this to calculate lead cost?
Yes. If your conversions are leads instead of sales, the result is your cost per lead. Just be consistent: divide spend by leads to get lead cost, or by closed customers to get customer acquisition cost.
What spend should I include?
Include the costs directly tied to acquiring customers in that period: ad budget, agency or freelancer fees, creative production, and acquisition software. Keep the definition steady from month to month so your CPA trend stays meaningful.
Are these numbers exact?
The math is exact, but the planning estimate assumes your future CPA matches your target. Real results shift with audience, season, and competition. Treat this as an educational estimate for budgeting, not a guarantee.