Free tool · Advertising metrics

Target CPA Calculator

Work out the most you can pay per order and the CPA to target if you want to keep a profit.

100% free
No sign-up
Runs in your browser

Average order value

Gross margin

Profit you want to keep per order

As a percentage of the order value, after ad costs.

Target CPA

$27.00

Use this as your Google Ads target CPA

Break-even CPA

$40.50

The most you can pay per order without losing money

Target ROAS equivalent

3.33x

What target CPA should I set in Google Ads?

CPA, or cost per acquisition, is what you pay in advertising to get one conversion. For an e-commerce store, the conversion is usually a purchase, so CPA is your ad cost per order. In Google Ads, Target CPA is also a Smart Bidding strategy: you tell Google the average cost per conversion you want, and it sets bids to hit it.

The problem is that many stores pick a target CPA by gut feel. This calculator derives it from your actual economics, so the number you enter in Google Ads leaves you a profit.

When to use the target cpa calculator

Best for

Setting a Target CPA bid strategy
Stores with similar product prices
Checking if a campaign can be profitable

Not the right pick for

Catalogs with widely varying order values — use Target ROAS
Judging growth sustainability — compare CAC with customer lifetime value

How it works

1
Enter AOV
Use your average order value.
2
Enter gross margin
Include shipping and fees in your costs.
3
Enter desired profit
Choose the profit margin to keep per order.
4
Read your results
See break-even CPA and target CPA.

How to calculate target CPA

Gross profit per order = Average order value × Gross margin %

Break-even CPA = Gross profit per order

Target CPA = Average order value × (Gross margin % − Desired profit margin %)

Break-even CPA is the maximum you can pay per order before the ad cost eats all of the order's gross profit. Target CPA leaves room for the profit margin you want to keep on each order.

Worked example

Your average order is $100, your gross margin is 45%, and you want to keep 15% of each order as profit after ad costs.

Metric	Calculation	Result
Gross profit per order	$100 × 45%	$45
Break-even CPA	—	$45
Target CPA	$100 × (45% − 15%)	$30

At a $30 CPA, each order leaves you $15 in profit after the product and the ad. At $45 you break even. Above $45, every ad-driven order loses money.

CPA vs CAC

The two are related but not the same:

CPA is the ad cost per conversion, measured in an ad platform. It counts every purchase, including repeat customers, and only includes media spend.
CAC (customer acquisition cost) is the total cost to win a new customer: ad spend plus related costs like agency fees, creative and tools, divided by new customers only.

CAC is usually higher than CPA because it has a bigger numerator and a smaller denominator. CPA is the right number for daily bidding; CAC is the right number for judging whether growth is sustainable, especially compared with customer lifetime value.

Interpreting your target CPA

A target CPA is only realistic if your traffic can support it. Check it against your click costs and conversion rate:

Expected CPA = CPC ÷ Conversion rate

If your average CPC is $1.20 and your conversion rate is 3%, your expected CPA is $40. That is above the $30 target in our example, so either the CPC must come down, the conversion rate must go up, or the target needs to be revisited. The CPC calculator shows the maximum profitable click cost for your numbers.

Things that legitimately shift your target:

Repeat purchases. If customers typically buy several times, you can accept a higher CPA on first orders.
Order value by campaign. Campaigns selling expensive products can support a higher CPA than those selling accessories. Use separate targets, not one account-wide number.
Target CPA vs Target ROAS. When order values vary widely, Target ROAS is often a better fit for Shopping and Performance Max, since it values a $300 order more than a $30 one. Target CPA treats them the same.

Tips to hit your target CPA

Improve conversion rate first. Faster product pages, clear shipping costs and good reviews lower CPA without touching bids.
Raise AOV. A higher order value increases both break-even and target CPA, giving bidding more room.
Start near your current CPA. Setting a target far below what you achieve today can sharply limit volume. Tighten in steps.
Give Smart Bidding enough data. Bidding generally performs better with a steady flow of conversions; very low-volume campaigns can be erratic.
Track purchases accurately. Missing or duplicate conversions make any CPA target meaningless.

Free tool vs having us run your Google Ads

	Free tool (do it yourself)	Mercantads does it for you
Know your numbers	Calculate them here	Targets set from your real margins and data
Campaigns	Learn and build them yourself	Shopping, Performance Max and Search built for you
Optimization	Whenever you find time	Weekly search terms, bids, budgets and feed updates
Results	Depends on your time and experience	A Google Partner team focused on your profit

Talk to us

FAQ

Frequently Asked Questions

There is no universal figure. A good CPA is one below your break-even CPA, which depends on your order value and margin; a $30 CPA is great for a $200 order and unprofitable for a $40 one.

Break-even CPA is the most you can pay per order without losing money. Target CPA is lower, because it reserves part of each order's gross profit as your actual profit.

If your products have similar prices, Target CPA can work well. If order values vary a lot, Target ROAS usually aligns bidding better with revenue and profit.

It should. Include those costs in your gross margin so the CPA you target reflects the profit you actually keep.

More free tools

All tools →

ROAS calculatorReturn on ad spend and profit after ads.Break-even ROAS calculatorThe minimum ROAS that keeps you profitable.Google Ads budget calculatorThe budget you need to hit a sales goal.POAS calculatorProfit on ad spend, the metric behind real profit.CPC calculatorYour cost per click and the most you can afford.CPM calculatorCost per thousand impressions.