ROAS in Marketing: What the Acronym Means, the Formula and the Break-Even Number Most Advertisers Skip
Return on ad spend explained with the arithmetic, the difference from ROI and how to set a target.
Published by AI Knows Us · Updated 13 October 2026
ROAS stands for return on ad spend. It tells you how much revenue you earn for each unit of currency you spend on advertising. The formula is revenue from ads divided by cost of ads. If you spend 1,000 USD on ads and those ads produce 4,000 USD in sales, your ROAS is 4, which is also written as 4:1 or 400 percent. The number only tells you whether the ads are profitable once you compare it with your break-even ROAS, which comes from your margin.
The formula, with Google's version
ROAS = revenue attributed to ads / advertising cost.
Google's help page on target ROAS defines the target as the average conversion value you would like to get for each dollar you spend on ads, and gives this example: 5 USD in sales divided by 1 USD in ad spend, multiplied by 100 percent, equals a 500 percent target ROAS. The page also says conversion tracking must be set up and that you must assign values to the conversions you track, because Google Ads uses reported conversion values to predict future ones.
Two notations are common, and they mean the same thing:
| Written as | Meaning |
|---|---|
| 5 or 5:1 | 5 units of revenue for each unit spent |
| 500% | The same ratio as a percentage, used inside Google Ads |
A worked example
These numbers are examples only, chosen to make the arithmetic easy.
- Ad spend in a month: 2,000 USD.
- Revenue recorded from those ads: 9,000 USD.
- ROAS = 9,000 / 2,000 = 4.5, or 450 percent.
The result looks healthy, but you cannot tell yet. The next section shows why.
ROAS is not profit: find your break-even ROAS
Revenue is not money you keep. A product that sells for 100 USD might cost 60 USD to buy or make and ship, leaving 40 USD of gross margin. Every sale gets you the margin, not the revenue. So:
Break-even ROAS = 1 / gross margin (as a decimal).
| Gross margin | Break-even ROAS | Meaning |
|---|---|---|
| 50% | 2.0 | You need 2 USD of revenue per 1 USD of ads to cover the product and the ad cost |
| 40% | 2.5 | 2.5 USD per 1 USD |
| 25% | 4.0 | 4 USD per 1 USD |
| 10% | 10.0 | 10 USD per 1 USD |
With a 25 percent margin, the 4.5 ROAS in the example above is only just above break-even and leaves little to pay for staff, software and overheads. With a 50 percent margin, the same 4.5 is comfortable. The same ROAS means different things for different products, which is why advertisers who compare themselves with an industry average often go wrong.
Work out your own margin first, then set the target ROAS above the break-even figure with room for the other costs you carry. Our guide to ecommerce PPC and margin shows how margin shapes the account.
ROAS compared with ROI and CPA
| Measure | Question it answers | Formula |
|---|---|---|
| ROAS | How much revenue per unit of ad spend? | Revenue / ad cost |
| ROI | How much profit per unit invested, after all costs? | Net profit / total cost |
| CPA | How much does each sale or lead cost? | Ad cost / conversions |
ROAS is quick and easy to calculate inside an ad platform, but it ignores costs outside advertising. ROI counts the full picture. CPA suits businesses where each lead or sale is worth about the same. Use ROAS for day to day ad decisions and ROI for budget decisions. See our guides to marketing return on investment and CPA in marketing.
Platform ROAS and blended ROAS
The number inside an ad platform counts the revenue that platform takes credit for. If a customer sees a social ad, then clicks a search ad and buys, both platforms may claim the sale. Two platforms can each report a strong ROAS while your total revenue did not move by that much.
To check, calculate a blended ROAS: total revenue for the period divided by total ad spend across all platforms. If the platform numbers add up to far more than your total revenue, the platforms are overlapping. Our guide to marketing attribution explains how to build a measurement plan around this.
How to improve ROAS
- Raise revenue per sale. Bundles, higher value products and free shipping thresholds lift the average order value.
- Cut spend where it does not return. Review by campaign, product and search term, and pause the bottom group.
- Improve the landing page. The same traffic with a higher conversion rate lifts ROAS without spending more.
- Target buyers who are closer to purchase. Branded search and past visitors usually return more than cold audiences, but they are limited in size.
- Fix tracking. Missing or duplicate conversions distort the number in both directions.
- Use value rules. Give Google the true value of each conversion, so the platform bids for the right customers.
When a high ROAS is the wrong target
If you only fund the campaigns with the highest ROAS, you tend to spend most on people who were likely to buy anyway, such as those who searched your name. Growth often needs spending on a lower ROAS audience that is new to you. Decide how much of the budget is for harvest, with a high target, and how much is for new customers, with a lower target that still stays above break-even.
Report ROAS monthly in one table
Keep a simple table with one row per campaign: spend, attributed revenue, platform ROAS, break-even ROAS and the gap between them. Add a final row for blended ROAS using total revenue from your shop or accounting system. Review it on the same day each month, mark campaigns below break-even for a decision, and write down the change you make so the next review shows whether it worked. A page of numbers with a decision beside each one is what finance teams ask to see.
Questions about ROAS
What does ROAS stand for?
Return on ad spend.
What is a good ROAS?
One that is comfortably above your break-even ROAS, which is 1 divided by your gross margin. A good number for one business can be a loss for another.
Is ROAS the same as ROI?
No. ROAS measures revenue per unit of ad spend. ROI measures profit after all costs.
How do I convert ROAS to a percentage?
Multiply by 100. A ROAS of 4 is 400 percent.
Why does my platform ROAS not match my sales?
Platforms can claim credit for the same sale and count conversions on different time windows. Compare with blended ROAS from your own sales data.
ROAS counts clicks, and assistants answer without them
ROAS can only credit sales that an ad touched. A buyer who asks an assistant for the best provider and then types your name into Google arrives as a branded search with a very high ROAS, and the ad gets the credit for a decision the assistant helped to make. AI Knows Us shows whether the assistants name you when buyers ask, so when your branded search ROAS moves, you can see whether the assistants' answers were part of the reason.