What is ROAS?

By the FlowMind Team · Updated June 2026 · 4 min read

Short answer: ROAS (return on ad spend) is the revenue you earn for every dollar of advertising. ROAS = revenue ÷ ad spend. A 4× ROAS means $4 back for every $1 spent — but whether that is good depends entirely on your margin.

Key takeaways

  • ROAS = revenue ÷ ad spend; a 4× ROAS means $4 back for every $1 spent.
  • ROAS is built on revenue, not profit — a healthy-looking ROAS can still lose money.
  • Break-even ROAS = 1 ÷ gross margin. That is the line you actually have to beat.
  • A very high ROAS often signals under-spending, not winning.
ROAS formula: revenue divided by ad spend, with a worked example of $4,000 revenue divided by $1,000 spend equals 4x ROAS

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ROAS is the metric everyone quotes and almost everyone misreads. It is simple to calculate and genuinely useful, but on its own it does not tell you whether you made money. Let us fix that.

How to calculate ROAS

Take the revenue attributed to a campaign and divide it by what you spent. Spend $2,000 and earn $8,000 in attributed revenue, and your ROAS is 4× (or 400%). That is the whole formula.

Why a high ROAS can still lose money

Here is the trap: ROAS is built on revenue, not profit. If your gross margin is 20%, a 4× ROAS turns $8,000 of revenue into $1,600 of gross profit — less than the $2,000 you spent. You were profitable on paper and underwater in reality. The fix is to know your break-even ROAS, which is simply 1 ÷ margin. At 20% margin you need 5× just to break even.

The ROAS / MER calculator shows your break-even ROAS next to your actual ROAS so the gap is obvious.

Common mistakes

FAQ

What is a good ROAS?
Anything above your break-even ROAS. We go deeper in what is a good ROAS.

Is ROAS the same as MER?
No. ROAS is usually per-channel; MER is blended across all spend. See ROAS vs MER.

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