How the ROAS Calculator works
ROAS is the inverse of ACoS: sales divided by ad spend. A ROAS of 4 means $4 of sales for every $1 of ads (25% ACoS).
ROAS on its own says nothing about profit. A 4× ROAS is excellent for a product with a 40% pre-ad margin and a loss for one with a 20% margin. Enter your margin before ads to get the break-even ROAS to compare against.
Formula
- ROAS = Ad sales ÷ Ad spend
- ACoS = 100 ÷ ROAS
- Break-even ROAS = 100 ÷ Margin before ads %
- Profit on ad sales = Ad sales × Margin before ads − Ad spend
Example
4× ROAS (25% ACoS) against a 2.86 break-even ROAS: ads earn about $200 profit.
Ad spend: 500Ad-attributed sales: 2000Margin before ads % (optional): 35
Frequently asked questions
Is a higher ROAS always better?
Per campaign, yes. But very high ROAS often means bids are too low to win volume; a lower ROAS with more sales can produce more total profit.
Amazon shows ROAS as a number and ACoS as a percent. Which should I use?
They contain the same information. Most Amazon sellers think in ACoS because it maps directly to margin.