ROAS calculator

How ROAS is calculated

ROAS shows how much revenue each unit of ad spend brings in. The formula is simple, but reading the result correctly requires knowing your margin.

ROAS is written in two formats: a ratio (4.5x) and a percentage (450%). Google Ads Target ROAS uses the percentage: a 450% target means 4.5 in conversion value is expected for every 1 spent.

Revenue here means the conversion value the ad platform or GA4 attributes to the campaign. That number depends on the attribution model — more in data-driven vs last click attribution.

Break-even ROAS: when ads make a profit

A high ROAS does not automatically mean profit. With a low product margin, even 4x ROAS can lose money. Break-even ROAS is the point where ads neither make nor lose money.

The margin here is the contribution margin: product cost, shipping, payment fees and other per-sale costs are subtracted. Fixed costs such as rent and salaries are not included.

If ROAS is above break-even, profit remains after ad spend. If it is below, every sale loses money even as sales grow.

Example: an online store

The numbers are hypothetical and only illustrate the calculation.

• Monthly ad spend: 1,000, revenue from ads: 4,500.
• ROAS = 4,500 / 1,000 = 4.5x (450%).
• Selling price 100, product cost 60, shipping and fees 15 → margin = 25 / 100 = 25%.
• Break-even ROAS = 1 / 0.25 = 4x. With 4.5x ROAS the campaign is profitable: 4,500 × 0.25 − 1,000 = 125.
• If you want 5% of sales left as net profit after ad spend: target ROAS = 1 / (0.25 − 0.05) = 5x (500%).

With a 20% margin, break-even ROAS would be 5x and the same 4.5x campaign would lose money. That is why a ROAS target always starts from the margin.

How to read the result

1. Find your break-even ROAS first — it is the campaign's minimum target.
2. If ROAS is below break-even, look at ROAS by product group, keyword and audience and isolate the loss-making segments.
3. If ROAS is well above break-even, there may be room to increase the budget — but ROAS usually changes as budget grows, so scale in steps.
4. When setting Target ROAS in Google Ads, convert the target to a percentage (5x → 500%) and give the strategy time to learn. More: running Performance Max without wasting budget.

Common mistakes

• Confusing ROAS with ROI. ROAS compares revenue with spend, ROI compares profit. 300% ROAS is not 300% profit.
• Treating platform revenue as real sales. Meta and Google can each claim the same sale. Check the total against GA4 and your CRM — see marketing KPIs and GA4.
• Ignoring VAT and returns. If revenue includes VAT or returns are not subtracted, ROAS looks higher than it really is.
• Comparing different attribution windows. ROAS on a 7-day click and 1-day view window is not the same as 1-day click ROAS.

Frequently asked questions