Comprehensive Guide
Learn more in our Business & Tax Guide.
How it works
Return on ad spend (ROAS) is the revenue generated for every dollar spent on advertising, calculated by dividing ad-attributed revenue by ad spend. Spend $8,000 and attribute $32,000 of revenue and the ROAS is 4x — four dollars back per dollar in. Its popularity comes from being a clean media-buying metric: platforms report it, budgets scale against it, and campaigns rank on it. But the clean surface hides two traps. First, attribution: platforms credit every click and view they can touch, so reported ROAS runs hotter than the bank account — blended MER, total company revenue over total ad spend, is the sober companion number. Second, ROAS ignores everything below the ad line. Product cost, shipping and fees come out of that 4x before anyone profits; on thin margins even 4x loses money, which is why serious operators pair ROAS with a break-even ROAS computed from their own unit economics. The calculator also converts spend into shares: ads as a percentage of revenue is the same fact seen through a CFO's eyes, and margin-after-ads shows what remains for goods, rent and payroll. Read all of them together — a falling marginal ROAS while budget scales is normal diminishing returns, not necessarily a failing campaign.Formula
ROAS = ad-attributed revenue / ad spend | ads as % of revenue = ad spend / ad revenue x 100
Tips
- Compare campaigns under one attribution model — mixing windows invents winners.
- Track blended MER alongside platform ROAS to see the gap attribution creates.
- Know your break-even ROAS before scaling anything against a target multiple.
- Judge trends, not snapshots: ROAS moves weekly with auctions and seasonality.
- Marginal ROAS falls as budgets grow — scale to the point it still clears costs.
Frequently asked questions
What does ROAS mean?
Return on ad spend — the revenue your advertising generates per dollar spent. Divide ad-attributed revenue by ad spend: $32,000 of attributed revenue on $8,000 spent is a 4x ROAS. It is the standard efficiency metric for paid campaigns.
How is ROAS calculated?
Divide the revenue attributed to your campaigns by what those campaigns cost over the same period. Multiply by 1 if you prefer a ratio (4x) or express it as a percentage (400%) — the underlying division is identical.
What is a good ROAS?
It depends entirely on margins. A business keeping 70% of each sale profits handsomely at 2x; one keeping 25% needs well above 4x. Calculate your break-even ROAS from unit economics first, then judge live numbers against that line, not against folklore targets.
Is ROAS the same as ROI?
No. ROAS compares revenue to ad spend only; ROI compares profit to total investment. A 4x ROAS on a product with heavy goods costs can produce negative ROI — which is why the two numbers must be read together rather than swapped.
Why does my ad platform report higher ROAS than my revenue actually grows?
Attribution. Platforms claim conversions influenced by views and clicks across their models, including sales that would have happened anyway. Cross-check with blended metrics like MER — total revenue over total spend — to see the unflattering truth.