Breakeven ROAS Calculator: The Formula, a Worked Table and Your Target

A breakeven ROAS calculator answers one question: how much revenue does each euro of ad spend need to bring back before the sale stops losing money? Below that line, every order from ads costs you more than it leaves behind. Above it, ads start paying for themselves. You do not need special software to work it out. A spreadsheet with six inputs is enough.

The catch is which margin you feed it. Most quick calculators use gross margin and set the line too low. This how-to builds the honest version, step by step, with a worked table. If you have not yet seen why platform numbers drift from your bank balance, start with why your ROAS doesn't match your profit.

Quick answer

Breakeven ROAS equals 1 divided by your margin as a decimal, so the answer depends on which margin you use. The quick version uses gross margin. The accurate version uses contribution margin, which also subtracts shipping, payment fees, packaging and expected returns. With a 48 percent contribution margin, breakeven ROAS is 1 ÷ 0.48, about 2.1.

What is breakeven ROAS?

Breakeven ROAS is the return on ad spend at which the margin from ad-driven sales exactly covers the money spent on those ads. At that point, advertising neither makes nor loses money before fixed costs.

The logic is short. If you keep 40 cents of every euro of revenue after variable costs, you need €2.50 of revenue to earn back €1 of ad spend. So:

• Breakeven ROAS = 1 ÷ margin %

A 50 percent margin means a breakeven ROAS of 2.0. A 25 percent margin means 4.0. The thinner your margin, the higher the bar your ads must clear.

Gross margin or contribution margin: which goes in the calculator?

The margin you plug in decides whether the result protects you or flatters you, so choose it with care before you trust any output. Two versions are common:

• Gross margin = (price − product cost) ÷ price. Quick and easy, but it ignores every cost between the warehouse and the customer.
• Contribution margin = (net revenue − all variable costs) ÷ net revenue. The Corporate Finance Institute defines contribution margin as sales revenue less variable costs, and lists shipping costs for customer orders among them.

For an online store, variable costs per order usually include:

• product cost, including inbound freight and duties
• shipping you pay to deliver the order
• payment processing fees
• packaging and pick and pack
• an allowance for returns and refunds

Leave ad spend out of the margin, since breakeven ROAS is what you compare ad spend against. Leave fixed costs out too: salaries, rent and software do not grow with each extra order. Our guide to contribution margin for ecommerce breaks these layers down in detail.

How do you build a breakeven ROAS calculator in a spreadsheet?

Building the calculator takes one row of inputs per product, one formula for contribution, and one division at the end. The figures below are illustrative only, chosen to show the method, not taken from a real store. Prices exclude VAT.

The payment fee line uses Stripe's published rate for standard EEA cards, 1.5% + €0.25. Your own provider and card mix will differ, so use your real invoices.

Now compare the two calculators side by side:

The gross-margin calculator says any ROAS above 1.43 is profitable. The contribution-margin calculator says you need 2.07. A campaign running at 1.8 looks like a winner on the first sheet and loses about €4.30 on every order on the second, before a single salary is paid.

In spreadsheet terms, put the inputs in cells B2 to B7 and use:

• Contribution per order: =B2-B3-B4-B5-B6-B7
• Contribution margin: =B8/B2
• Breakeven ROAS: =1/B9

Why do returns change the answer so much?

Returns are the cost most founders forget, because the refund arrives weeks after the ad platform has already counted the sale as revenue. In December 2024, NRF and Happy Returns projected that US retail returns would reach $890 billion in 2024, across the whole industry.

Your own return rate may be far lower or far higher, depending on category. Clothing with size issues sits at one end, consumables at the other. Use your own trailing 90-day refund rate, and include return shipping if you pay it. In the table above, dropping the returns allowance alone would cut breakeven ROAS from 2.07 to about 1.77.

How do you set a target ROAS above breakeven?

A target ROAS sits above breakeven by enough to pay your fixed costs and leave a profit, so you set it from your own overheads rather than from a benchmark. The formula is a small extension of the breakeven one:

• Target ROAS = 1 ÷ (contribution margin % − profit goal %)

Here, the profit goal is the share of revenue you want left after ad spend to cover fixed costs and profit. Using the worked example, with a contribution margin of 48.4 percent:

On Google Ads, enter the result as a percentage: a target of 3.0 becomes 300 percent. Google's help centre also advises basing the figure on your business goals and past ROAS, and allowing one to two conversion cycles after a change before judging results.

Two practical rules help:

1. Compare like with like. Platform ROAS counts attributed revenue before refunds. If your margin already includes a returns allowance, judge platform ROAS against your target with that in mind, or better, judge store-side blended ROAS. Our MER vs ROAS guide covers the difference.
2. Allow a planned exception for first orders. Some brands accept a first-order ROAS below breakeven because repeat purchases follow. Make it a written decision with a payback period, not an accident.

Common mistakes with breakeven ROAS calculators

Most breakeven errors come from inputs rather than arithmetic, so a correct formula can still give you a dangerously wrong line. Check for these:

• Using list price instead of the price after discounts. A 20 percent code changes the margin, not just the conversion rate.
• Counting VAT as revenue. It inflates both the price and the margin.
• One number for the whole catalogue. A store-wide breakeven ROAS hides products that can never clear their own line. See how a per-SKU profit teardown exposes them.
• Setting it once. Supplier prices, carrier rates and return rates move. Recalculate monthly.

Where Wevion fits

Keeping a breakeven calculator current by hand means re-exporting costs and spend every week, and the sheet is out of date the moment a supplier invoice changes.

Wevion connects Meta, Google, TikTok, Taboola, Snapchat and Outbrain through each platform's official API with OAuth, pulls Shopify or WooCommerce orders and revenue next to that spend in one dashboard, and syncs about every 15 minutes, so the inputs to your breakeven line are already joined in one place.

On top of that, Wevion's Profitability Analytics, currently in beta, uses cost per item from your store plus the shipping and fees you set once to show profit, margin and POAS, with break-even POAS worked out. For the full setup, see Shopify profit tracking from ROAS to POAS.

Key takeaways

The five points below sum up how to build a breakeven ROAS calculator you can trust and turn it into a target.

• Breakeven ROAS = 1 ÷ margin. The margin you choose matters more than the formula.
• Use contribution margin, after product cost, shipping, payment fees, packaging and returns, not gross margin.
• In the illustrative example, switching from gross to contribution margin moved breakeven ROAS from 1.43 to 2.07.
• Target ROAS = 1 ÷ (contribution margin − profit goal), so it covers fixed costs and profit.
• Work out breakeven per product line and recalculate monthly as costs move.

Want your costs, orders and ad spend in one view instead of a spreadsheet? Start a 14-day free trial of Wevion on the Pro plan, no card needed.