ROAS means return on ad spend. You take the revenue attributed to a campaign and divide it by the media budget that campaign used. The answer is usually written as a ratio, such as 3.5, or as a percentage, such as 350 percent, and both say the same thing.
The metric lives mostly in ecommerce and in any business where a conversion carries a known value. Google Ads, Meta and Amazon all report it next to each campaign, and many advertisers use it as the goal for automated bidding.
ROAS looks at revenue, not profit. It ignores product cost, shipping, returns, staff time and fees, which is why it is a narrower number than ROI. It tells you how hard the ad budget is working, not whether the business made money on the sale.
Mechanics
What pushes ROAS up or down
Three inputs drive the ratio: what each click costs, how many visitors buy, and how much each buyer spends. Written out, ROAS equals conversion rate times average order value, divided by cost per click. Lower click prices, a stronger checkout or bigger baskets all lift the result.
The revenue side depends on tracking. The platform only counts sales it can connect to an ad, within its own lookback window and under its own attribution rules. Two platforms can each claim the same order, so adding their reported revenue together often produces more sales than the store actually recorded.
To know what ROAS you need, start from gross margin. Break-even ROAS is 1 divided by the margin. A product line with a 40 percent margin breaks even at 2.5, because only 40 of every 100 in revenue is left to pay for the ads.
Example
A worked example for an online store
Assume a store selling kitchen tools spends 6,000 on Shopping campaigns in a month. The platform credits those campaigns with 240 orders, and the orders total 21,600 in revenue. ROAS is 21,600 divided by 6,000, which is 3.6.
Now bring in margin. Say the store keeps 35 percent of revenue after product cost and shipping. That leaves 7,560 of gross profit on the tracked orders. Subtract the 6,000 in ad spend and 1,560 remains before rent, payroll and software.
The break-even point for this store is 1 divided by 0.35, roughly 2.86. A campaign reporting 3.6 clears it, but not by much. If returns take back 10 percent of those orders, revenue drops to 19,440, ROAS falls to 3.24, and the cushion above break-even is roughly cut in half.
Use
When ROAS helps and when it misleads
- Use it to compare campaigns selling products with similar margins, where a higher ratio really does mean more money left over.
- Use it as a bidding target once purchase tracking passes real order values, not a fixed placeholder value for every sale.
- It misleads when margins differ widely across the catalog, because a 5 on low margin goods can earn less than a 3 on high margin goods.
- It misleads for subscriptions and repeat purchase brands, where the first order is small and most of the value comes later; pair it with LTV.
- It flatters branded search and retargeting, which often catch people who would have bought anyway, so read those campaigns separately.
Watch out
Common mistakes with ROAS
- Setting one ROAS target for the whole account without first calculating break-even from the margin of each product group.
- Summing the revenue claimed by every ad platform and treating the total as real sales, which double counts shared orders.
- Pushing the target so high that campaigns only reach existing customers, which keeps the ratio pretty while new customer growth stalls.
- Ignoring returns, discounts and cancellations, so the revenue in the report is larger than the revenue that stays in the bank.
- Reading ROAS for a single week in a low volume account, where a few large orders can swing the ratio in either direction.