CPA calculator
CPA is what you pay to win one customer or sale. Enter your spend and conversions to get yours in a second.
CPA = ad spend ÷ conversions
Purchases, leads or sign-ups.
Fill in the boxes and your result appears here, instantly.
How many different ads can your budget test?
Enter your budget to see how many distinct ads it can test.
How to use the CPA calculator
- 1Enter your total ad spend for the period.
- 2Enter the number of conversions, such as purchases, from the same period.
- 3Read your cost per acquisition.
- 4Compare it with the profit on one order to see whether you are ahead.
How CPA is calculated
Cost per acquisition is ad spend divided by conversions. Spending $2,400 to get 80 purchases is a CPA of $30.
A conversion can be whatever matters to you: a purchase, a lead, a sign-up. Keep the definition consistent so you can compare periods fairly.
What to compare it with
A CPA is neither good nor bad on its own. Compare it with how much profit one order leaves you after product cost, shipping and fees. If you make $45 per order and your CPA is $30, each sale earns $15 before overhead. If your CPA is $60, each sale loses money.
For repeat-purchase businesses, compare it with the profit a customer brings over time, not just the first order.
Why your CPA changes
CPA is the combined result of CPM, click-through rate and conversion rate, so a change in any one of them moves it. Creative fatigue is a common cause: the same ad shown to the same people gets fewer clicks, and CPA drifts up.
Fresh, distinct creative is the standard fix. It lets Meta find new buyers and gives you a clearer view of which angle earns sales at an acceptable price.
Setting a target CPA
Work backward from profit. Take the profit you make on an average order, decide how much of it you are willing to spend on winning the customer, and that is your target CPA. A brand with a $45 profit per order might set a target of $25 and keep $20 per sale.
Review the target every few weeks. Prices, shipping costs and conversion rates change, and so should the line you hold your ads to.
Frequently asked questions
- What is the CPA formula?
- CPA equals total ad spend divided by the number of conversions.
- What is a good CPA?
- A good CPA is one comfortably below the profit you make on an order, or below customer lifetime value for repeat-purchase brands. It differs a lot between industries.
- Is CPA the same as CAC?
- They are close. CPA usually refers to the ad cost of one conversion, while CAC is often broader and includes team and software costs of acquiring a customer.
- How do I lower my CPA?
- Improve the part of the chain that is weakest: cheaper reach, a higher click-through rate, or a better landing page and offer. Testing new creative angles addresses the first two.
- Does Meta use CPA?
- Meta reports cost per result, which is CPA for the conversion event you optimize for. You can also set a cost per result goal to guide delivery.
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