Mockingbird

CPA calculator for Facebook ads

CPA (cost per acquisition) is your ad spend divided by the number of conversions it produced. Spend £2,000, get 64 sales, and your CPA is £31.25.

The useful question is whether that CPA is below your break-even CPA, the most you can pay for a sale and still make money on the first order. This calculator shows both.

Your campaign

Cost per acquisition

£31.25

Ad spend / conversions.

Break-even CPA

£30.00

Average order value times margin. Pay more than this per sale and you lose money on the first order.

Headroom per sale

-£1.25

Loss per sale after ad spend.

Conversions you could afford

67

Spend / break-even CPA: the fewest sales this spend needs to break even.

CPA = ad spend / conversions. If customers buy again, you can afford a higher CPA than the first order suggests. Worked out in your browser.

How to use CPA

CPA = ad spend / conversions. A conversion can be a purchase, a lead or a sign-up, so compare CPAs only between campaigns that optimise for the same event.

Break-even CPA = average order value x gross margin. If your CPA is under it, each sale makes money before any repeat purchase. If it is over, you are buying customers at a loss and need either better ads, a bigger order or confidence that customers come back.

Lowering CPA

CPA falls when more of the people who see your ad act on it. The biggest levers are in the ad itself:

  • A clearer hook in the first line and the top third of the image. See /guides/meta-ad-hooks.

  • A product people can recognise, shown with your real photos rather than a lookalike.

  • A landing page that matches the promise in the ad.

Frequently asked questions

How is CPA calculated?
Divide total ad spend by the number of conversions. £2,000 of spend and 64 purchases gives a CPA of £31.25.
What is a good CPA for Facebook ads?
Any CPA below your break-even CPA, which is your average order value multiplied by your gross margin. There is no universal good number, because margins differ so much between products.
Is CPA the same as cost per result in Ads Manager?
Cost per result is Meta's name for the cost of whatever result your campaign optimises for. When the result is a purchase, cost per result and CPA are the same thing.

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