The one-line formula

ROAS, or return on ad spend, is revenue divided by ad spend. Break-even ROAS is the ROAS at which the profit from the sales exactly covers the ads that produced them. The formula is:

Break-even ROAS = 1 ÷ contribution margin.

If 40 cents of every sales dollar is left after the costs of making and delivering the order, your contribution margin is 40%, or 0.4. One divided by 0.4 is 2.5. A campaign needs at least a 2.5x ROAS, $2.50 in sales for every $1 of ads, before it earns a cent.

What goes into contribution margin

Contribution margin is the share of each sale left after every cost that rises and falls with that sale. It is stricter than gross margin, which usually subtracts only the product itself. For an online store, include:

  • Cost of the product, or the materials and labor to make it.
  • Shipping and packaging you pay for.
  • Payment processing fees, typically a few percent of each order.
  • Marketplace or platform fees charged per sale.
  • An allowance for returns and refunds, based on your own history.
  • Discounts given on the order.
Break-even ROAS at different contribution margins
  • 20% margin5x
  • 30% margin3.33x
  • 40% margin2.5x
  • 50% margin2x
  • 60% margin1.67x
  • 70% margin1.43x

A calculation, not survey data: each bar is 1 divided by the contribution margin, the minimum ROAS before a campaign earns any profit.

Source: Worked example

A worked example

Say you sell a $100 product. It costs you $45 to buy, $8 to ship and $3 in payment fees, and you lose about $4 per order on returns. That leaves $40, a 40% contribution margin. Break-even ROAS is 2.5x.

Now look at a campaign that spent $2,000 and your store records show $4,400 in sales from it, a 2.2x ROAS. It feels positive, since more money came in than went out. But 40% of $4,400 is $1,760 of contribution, which is $240 less than the $2,000 you spent. The campaign lost money. If you had used gross margin alone, 55% here, you would have calculated a break-even of about 1.8x and wrongly called it a winner.

The chart on this page shows how quickly the bar rises as margins shrink. At 70% you need about 1.4x. At 20% you need 5x.

Why your industry matters

Margins vary enormously between businesses, which is why there is no universal good ROAS. NYU Stern professor Aswath Damodaran's January 2026 data on US companies shows an average gross margin of 56.88% for apparel but 26.31% for grocery retail. Even before shipping and fees, that puts the apparel break-even near 1.8x and grocery near 3.8x. A 3x ROAS is comfortable profit for one and a steady loss for the other.

So a ROAS target borrowed from a forum, an agency's other client, or an ad platform's suggestion can be badly wrong for you. Work out your own number. Our explainer on ROAS vs. ROI covers how the two connect.

From break-even to a target

Break-even is a floor, not a goal. Contribution margin does not cover rent, salaries or software, so set your target ROAS above break-even by enough to pay for those and leave profit. A simple way to find that cushion is to add your monthly fixed costs to the ad spend and ask what ROAS would cover both.

If you use automated bidding, the target matters even more. Google Ads lets you set a target ROAS, which it describes as "the average conversion value (for example, revenue) you'd like to get for each dollar you spend on ads". Google expresses it as a percentage, so a 2.5x break-even is a 250% target ROAS. Setting it below break-even tells the system to buy sales at a loss.

Two cautions. First, measure ROAS with sales you can verify, because ad platforms often count more sales than you made (why that happens). Second, if customers come back to buy again, a first-order ROAS below break-even can still pay off over time; check it against customer lifetime value before cutting a campaign.

Matrix ROI, a Smith App Studio product, shows platform-claimed sales beside your verified Stripe or store sales each day, so the ROAS you compare with break-even rests on real revenue.