What ROAS do your ads actually need to hit?
Break-even ROAS comes from your margin: 1 divided by your contribution margin per order. Answer a few questions and get three numbers: the ROAS where ads stop losing money, the ROAS that hits your profit target, and the first-order ROAS you can accept if repeat purchases are real.
Your margin sets break-even ROAS. Divide 1 by your contribution margin per order and you have the revenue multiple every ad dollar has to return before it stops losing money. Two variants sit around it: a profit-target ROAS that also leaves you a slice of the revenue, and an LTV-adjusted floor that credits repeat orders on the first sale.
- Formula: break-even ROAS = 1 divided by contribution margin per order, expressed as a decimal.
- Profit-target ROAS = 1 divided by (contribution margin minus the share of ad-driven revenue you want to keep). If the target exceeds your margin, no ROAS can deliver it, and margin is the lever to pull.
- LTV-adjusted break-even = 1 divided by (contribution margin x lifetime orders), the first-order ROAS you can accept when repeats finish the payback.
- Inputs: contribution margin per order %, lifetime orders per customer, profit keep-rate %, and your current blended ROAS for the comparison.
- Healthy band: under 2.5x means real headroom, 2.5x to 4x is workable but fragile to rising CPMs, over 4x means almost no paid channel clears it sustainably.
- Common mistake: judging platform ROAS instead of blended. Every channel claims the conversions it touched, so the number to judge against the same floor is MER: total ad-driven revenue divided by total all-in spend.
How the number is calculated
All three thresholds come from your margin. Break-even ROAS is 1 divided by your contribution margin per order (as a decimal): at 38%, that's about 2.6x. For a profit target, subtract what you want to keep before dividing: keeping 10% of ad-driven revenue at a 38% margin gives 1 / 0.28, about 3.6x. Divide the floor by your lifetime orders and you get the LTV-adjusted break-even, the first-order ROAS you can accept when repeat purchases finish the payback. The bands below come from the brands I've operated and advised.
The same math works blended: divide total revenue by total marketing spend and you have MER, judged against the identical floor. Your ROAS floor converts directly into a CAC ceiling in the max allowable CAC calculator, and the DTC profitability calculator rebuilds the margin structure underneath it. All of the free DTC calculators share these benchmarks.