CPA Calculator
Calculate your cost per acquisition — and compare it against the maximum you can afford to pay for an order.
Your numbers
Optional — unlocks the profitability check
Results
Add selling price and costs to compare your CPA against break-even.
The CPA formula
CPA = Ad spend ÷ Orders
CPA (Cost Per Acquisition) is what one paying customer costs you in advertising. If you spend $200 on ads and get 10 orders, your CPA is $20.
The CPA becomes meaningful next to your break-even CPA — your contribution margin per order (selling price minus product, shipping and fee costs). That's the ceiling your CPA must stay under.
How to use this calculator
- 1
Enter your ad spend for a period or campaign.
- 2
Enter the number of orders those ads generated.
- 3
Optionally add selling price and per-order costs — the calculator shows your break-even CPA, your profit per order after ads, and a clear verdict.
CPA vs. ROAS — which one should you watch?
Both describe the same performance from different angles: ROAS is a revenue multiple, CPA is an absolute dollar amount per order. With a fixed product price, one can be converted into the other.
CPA thinking shines when your order value is stable — typical for one-product dropshipping stores. It answers the sharpest question there is: 'How much may one customer cost me?'
ROAS thinking fits better when order values vary a lot. Most professional buyers track both, with CPA as the hard guardrail per campaign.
How to lower your CPA
Better creatives beat better bids: the ad that stops the scroll lowers your CPA more reliably than any bidding trick.
Improve the funnel after the click — page speed, clear offer, trust signals. Every extra percent of conversion rate cuts your CPA proportionally.
And remember the other side of the equation: raising your average order value increases your break-even CPA, giving the same ads more room to be profitable.
Frequently asked questions
What is a good CPA?
One that sits comfortably below your break-even CPA — the contribution margin of one order. A $20 CPA is excellent for a product with a $35 margin and fatal for one with a $12 margin. There is no universal benchmark.
Is CPA the same as CAC?
They're closely related. CPA usually measures the ad cost of one conversion (an order); CAC (Customer Acquisition Cost) measures the full cost of winning one new customer and is often calculated across all marketing channels. For a single paid channel they're frequently used interchangeably.
How do I calculate my break-even CPA?
Selling price minus all per-order costs (product, shipping, payment and platform fees). The result is the maximum you can pay in advertising for one order without losing money. Our BEROAS calculator computes it alongside your break-even ROAS.
My CPA is above break-even. Should I kill the campaign?
Not automatically — first check whether the campaign is still learning, whether the audience is right, and whether your funnel converts. But scaling a campaign that's above break-even CPA means scaling a loss.