Most people judge ads by ROAS without knowing the only ROAS number that matters: the one where they stop losing money. That's break-even ROAS, and once you know yours, every ad decision gets simpler, cut, keep, or scale.
What break-even ROAS is
ROAS (return on ad spend) is revenue ÷ ad spend. A 3x ROAS means $3 back for every $1 spent. Break-even ROAS is the point where the profit you make on an order, before advertising, exactly equals what you paid to get it. Above it you profit; below it you lose money on every sale, no matter how good the ROAS "looks."
Calculate it in three steps
- Find your contribution margin before ads. Take your selling price and subtract product cost, shipping you pay, payment/processing fees, and any other per-order variable cost.
- That margin is your break-even CPA, the most you can pay to acquire one order and still break even.
- Break-even ROAS = selling price ÷ contribution margin (the same as 1 ÷ your margin %).
The break-even ROAS calculator does this instantly, but do it by hand once so the logic sticks.
A worked example
| Line | Amount |
|---|---|
| Selling price | $60.00 |
| Product + shipping cost | −$18.00 |
| Payment fees (2.9% + $0.30) | −$2.04 |
| Contribution margin | $39.96 |
Break-even CPA = $39.96. Break-even ROAS = 60 ÷ 39.96 ≈ 1.50x. So a "2x ROAS" here is genuinely profitable, while a "1.3x ROAS" is quietly losing money, even though 1.3x sounds positive.
Why it decides everything
Break-even ROAS turns a fuzzy question ("is this ad good?") into a clear one ("is it above or below 1.50x?"). It sets the line for cutting losers, the target for scaling winners, and the reason two stores can run identical ROAS with completely different outcomes, the one with better margins simply has a lower bar to clear.
Break-even is a floor, not a goal
Two costs aren't in the formula above, and both push the ROAS you truly need higher:
- Fixed costs, apps, subscriptions, and your own time. They don't change per order, but they still have to be paid.
- Returns and refunds, a 5% refund rate quietly raises your real break-even.
So treat break-even ROAS as the line below which you're definitely losing money, and set your actual target ROAS above it with room for the costs the formula ignores and the profit you actually want.
Putting it to work
Calculate your break-even once, write it on a sticky note, and judge every campaign's CPA and ROAS against it. Then make sure each ad has had enough spend to trust the number before you act, see how much to spend before judging an ad.
Learn this on live campaigns, with mentorship
The Masterclass covers testing, reading metrics, and when to cut or scale, inside a private Discord you can ask questions in before you buy.
Written by Ray. Ray mentors inside Shopify Scale, focusing on store conversion and paid-ads testing.