ROAS, return on ad spend, tells you how much revenue each dollar of advertising brings back. It is the most quoted ad metric and one of the most misread, because revenue is not profit. Pairing ROAS with break-even ROAS fixes that: break-even tells you the ROAS you need just to cover costs.
The formulas
ROAS = revenue from ads / ad spend. As a multiple: $10,000 revenue / $2,500 spend = 4.0x. As a percentage: 4.0 x 100 = 400%. Both say the same thing; multiples are more common in conversation, percentages in reports.
Break-even ROAS = 1 / contribution margin. Contribution margin is the share of revenue left after variable costs like product, shipping, and payment fees. With a 40% margin: break-even ROAS = 1 / 0.40 = 2.5x. Below 2.5x the ads lose money; above it they make money, before fixed costs.
Worked example
A campaign spends $2,500 and generates $10,000 in revenue. ROAS = 4.0x (400%). With a 40% contribution margin, break-even ROAS is 2.5x, so the campaign clears break-even comfortably: gross profit from the campaign is $10,000 x 0.40 = $4,000, minus $2,500 spend = $1,500 profit before fixed costs.
Now change one input: same revenue, but margin only 20%. Break-even ROAS = 1 / 0.20 = 5.0x. The same 4.0x ROAS now loses money: profit = $10,000 x 0.20 – $2,500 = -$500. Identical ROAS, opposite verdict. That is why ROAS without margin is meaningless.
What ROAS misses
ROAS usually credits only directly tracked revenue, missing repeat purchases, word of mouth, and brand effects that arrive later. It also ignores returns and cancellations if you count gross revenue. And it says nothing about incrementality: some of those sales might have happened without the ads. For a fuller picture, track ROAS alongside new-customer rate, repeat purchase rate, and profit per campaign, not just revenue per dollar.
Attribution windows matter too. A 7-day window and a 28-day window give different ROAS for the same campaign. Compare campaigns only on the same window and the same revenue definition.
Improving ROAS honestly
Raise ROAS by improving the offer, the landing page, or the targeting, not by cutting spend on the campaigns that bring new customers. Cutting spend raises ROAS mechanically while shrinking the business. And beware of optimising for ROAS alone: the highest-ROAS campaigns are often tiny retargeting pools, while the growth comes from broader, lower-ROAS prospecting. Judge the portfolio, not each campaign in isolation.
ROAS targets by funnel stage
Different campaign types deserve different ROAS targets. Prospecting campaigns that find new customers usually show lower ROAS, because the audience is cold. Retargeting campaigns that show ads to past visitors usually show higher ROAS, because the audience is warm.
Judging both by one target misleads in both directions: prospecting looks like a failure and retargeting looks like a miracle, when in fact retargeting harvests demand prospecting created. Set a blended portfolio target instead, and judge each campaign against the target for its stage. Growth comes from the portfolio, not from any single campaign’s ROAS.
A final reporting habit: always state the revenue definition beside the ROAS figure. Revenue counted at order placement differs from revenue counted after returns, cancellations, and refunds, and the gap can be several percentage points. A ROAS of 4.0x on gross orders might be 3.6x on net collected revenue, which changes the break-even verdict for thin-margin businesses.
Try it faster with the tool
You can follow every step above by hand, but the free ROAS Calculator — Return on Ad Spend as × and %, Plus Your Break-Even ROAS does the arithmetic for you. Enter your numbers and it gives the answer right away, so you can check your hand calculation or skip straight to the result.
Quick tips
- ROAS = revenue / ad spend.
- Break-even ROAS = 1 / contribution margin.
- ROAS without margin is meaningless.