What Is ROAS (Return on Ad Spend)?
ROAS (return on ad spend) is the revenue earned for every dollar spent on advertising, calculated as ad-attributed sales divided by ad spend; a ROAS of 4 means $4 in sales for each $1 of ads.
Formula: ROAS = attributed ad sales ÷ ad spend.
Example: $1,200 in ad sales from $300 of spend gives a ROAS of 4, often written 4x or 400%.
ROAS and ACoS
ROAS is the inverse of ACoS: ROAS = 1 ÷ ACoS, with ACoS as a decimal. A 25% ACoS equals a ROAS of 4, and a 20% ACoS equals a ROAS of 5. Amazon Ads reports both. Teams that also run Google and Meta often prefer ROAS because those platforms use it, while sellers who think in margin tend to prefer ACoS.
Why it matters
ROAS makes channels easy to compare, for example Sponsored Products against Amazon DSP or Google Ads sending traffic to Amazon. Break-even ROAS is 1 divided by your margin before ad spend: at a 30% margin it is about 3.3.
Common mistake
Comparing ROAS across ad types without checking the attribution window and whether view-through sales are included. A display campaign that counts views can look far better than a search campaign that counts only clicks. Our comparison of ACoS, ROAS and TACoS shows when to use each metric.