The short answer
- ROAS = revenue from ads / ad spend. ROI = (return - total cost) / total cost.
- ROAS measures revenue against ad spend only; ROI measures profit against every cost, so a high ROAS can still be a negative ROI.
- They diverge because of margin, overhead and time: product cost, fees, agency and tool costs, and customer lifetime value.
- Your break-even ROAS is 1 / contribution margin. At a 40% margin, you need a ROAS of 2.5 just to cover ad spend.
ROAS tells you how much revenue each ad dollar brought in. ROI tells you whether you made money. A campaign can post a 4.0 ROAS and still lose money if the product margin is thin.
Use ROAS to steer campaigns day to day. Use ROI to decide how much to spend in total.
ROAS and ROI defined
| ROAS | ROI | |
|---|---|---|
| Formula | Revenue from ads / ad spend | (Return - total cost) / total cost |
| Numerator | Revenue (top line) | Profit after costs |
| Costs counted | Ad spend only | Ad spend plus product cost, fees, tools, people |
| Usual format | Ratio (4.0 or 4:1) or percent (400%) | Percent (can be negative) |
| Best for | Comparing campaigns, ads and channels day to day | Deciding whether marketing makes money at all |
| Can look good while losing money | Yes | No, if every cost is included |
ROAS formula
ROAS = revenue attributed to ads / ad spend
$20,000 in revenue from $5,000 of ads is a ROAS of 4.0, also written 4:1 or 400%. The ROAS glossary entry covers how platforms attribute that revenue.
ROI formula
ROI = (gross profit from the campaign - total marketing cost) / total marketing cost
The definition of "return" is where teams disagree. For marketing, use gross profit, meaning revenue minus product cost and variable fees, not revenue. Using revenue in the ROI numerator turns it back into ROAS.
Why ROAS and ROI diverge
1. Margin
ROAS uses revenue; ROI uses profit. A $100 sale with $70 in product, shipping and payment costs leaves $30. A 3.0 ROAS on that product means $3 of revenue per $1 of ads, which is $0.90 of contribution per $1 spent. You lose ten cents on every ad dollar.
2. Overhead
ROAS counts only media spend. ROI should count agency fees, software, creative production and the time of the people running the campaigns. On a small budget, those costs can be a large share of total spend.
3. Lifetime value
ROAS usually looks at the first purchase inside an attribution window. If customers come back, the first-order ROAS understates the return. Subscription and repeat-purchase businesses should look at ROI on lifetime gross profit, not first order. Estimate yours with the LTV calculator.
4. Attribution and incrementality
Platform-reported ROAS counts sales the platform can attribute to an ad, including some that would have happened anyway, like branded searches from existing customers. Incremental ROAS counts only the sales the ads caused, which is the core idea behind incrementality testing. See incremental ROAS for how to estimate it with holdout tests. A campaign with a strong reported ROAS and a weak incremental ROAS is spending money on customers you already had.
Break-even ROAS
Break-even ROAS is the ROAS at which ad spend exactly equals the contribution it brings in. Below it, every sale from ads loses money.
Break-even ROAS = 1 / contribution margin
Contribution margin is the share of revenue left after product cost, shipping, payment processing and other per-order costs. Write it as a decimal.
| Contribution margin | Break-even ROAS | Means |
|---|---|---|
| 80% | 1.25 | $1.25 of revenue per $1 of ads to cover ad spend |
| 60% | 1.67 | $1.67 per $1 |
| 50% | 2.00 | $2.00 per $1 |
| 40% | 2.50 | $2.50 per $1 |
| 30% | 3.33 | $3.33 per $1 |
| 20% | 5.00 | $5.00 per $1 |
Two things follow from the table:
- Low-margin businesses need a high ROAS just to stand still. A 20% margin reseller at a 4.0 ROAS is losing money on ads.
- High-margin businesses, like software, can run at a low first-order ROAS and still profit, especially when customers renew.
Break-even ROAS covers ad spend only. To set a target ROAS that also covers overhead and a profit goal, use: target ROAS = 1 / (contribution margin - target profit margin - overhead as a share of revenue). At a 50% contribution margin, a 10% profit goal and 5% overhead, target ROAS = 1 / 0.35 = 2.86.
Worked examples
Example 1: a store with a 5.0 ROAS
An online store spends $10,000 on ads in a month and the platforms attribute $50,000 in revenue.
| Line | Amount |
|---|---|
| Ad revenue (attributed) | $50,000 |
| Ad spend | $10,000 |
| ROAS | 5.0 |
| Product cost (45% of revenue) | $22,500 |
| Shipping and payment fees (15% of revenue) | $7,500 |
| Contribution after ad spend | $10,000 |
| Agency fee and tools | $3,000 |
| Profit from marketing | $7,000 |
| Total marketing cost (ads + agency + tools) | $13,000 |
| Marketing ROI | $7,000 / $13,000 = 54% |
The 5.0 ROAS translates to a 54% marketing ROI. Contribution margin is 40% (100% minus 45% product cost minus 15% fees), so break-even ROAS is 2.5, and the store is double it. Good month.
Example 2: same ROAS, thinner margin
Change only the product cost to 65% of revenue. Contribution margin falls to 20%, and break-even ROAS rises to 5.0.
- Contribution before ads: $50,000 x 20% = $10,000
- Minus $10,000 ad spend = $0
- Minus $3,000 agency and tools = -$3,000
- ROI = -$3,000 / $13,000 = -23%
Same 5.0 ROAS in the ad platform. A loss in the bank account.
Example 3: low first-order ROAS, positive lifetime ROI
A subscription brand acquires customers at a $45 cost. The first order is $60 at a 50% contribution margin, so the first order contributes $30 and first-order ROAS is $60 / $45 = 1.33, below the 2.0 break-even.
But the average customer stays for four orders. Lifetime contribution is 4 x $30 = $120. Lifetime ROI is ($120 - $45) / $45 = 167%. Cutting this campaign based on first-order ROAS would cut the most profitable customers.
Which metric to use when
- Daily and weekly campaign decisions: ROAS, against a target derived from your break-even. It is fast, available in every ad platform, and fine for comparing campaigns with the same margin.
- Products with different margins: ROAS targets per product group, or bid on profit if your platform supports it. One account-wide ROAS target overspends on low-margin products.
- Monthly and quarterly budget decisions: ROI, with all costs included. This is the number that says whether to spend more.
- Repeat-purchase and subscription businesses: ROI on lifetime gross profit, alongside CAC payback.
- Testing whether a channel works at all: incremental ROAS from a holdout test.
Common mistakes
- Treating 1.0 ROAS as break-even. A 1.0 ROAS means revenue equals ad spend, so you lose the entire product cost on every sale.
- Using revenue in the ROI formula. That is ROAS with extra steps.
- Summing ROAS across platforms. Google and Meta can both claim the same order. Total attributed revenue across platforms can exceed real revenue. Check against your store or CRM.
- Ignoring returns and refunds. Net them out of revenue before computing either metric.
- Leaving people out of ROI. If a full-time marketer runs the ads, their cost belongs in the denominator.
Tracking ROAS and ROI in practice
Start with the ROAS calculator to get your break-even and target ROAS from your margin. Set that target in your campaigns, and review it against real profit monthly.
Sprites, an AI marketing agent, reads ROAS and conversion data in your connected Google Ads, Meta and Microsoft accounts, flags campaigns running below the target you give it, and proposes budget and campaign changes as editable approval cards. Nothing changes until you approve it. Your product margins and overhead live outside the ad platforms, so tell it your contribution margin and it will judge campaigns against your break-even rather than a generic number.
Write your contribution margin down, divide 1 by it, and compare every campaign's ROAS to that number this week.