Amazon ACoS Calculator
Calculate your Advertising Cost of Sale, ROAS, and break-even ACoS from ad spend, ad-attributed sales, and profit margin. Free, no signup.
ACoS calculator
ACoS
20.0%
ROAS
5.00x
Break-even ACoS
35.0%
Profitable on ad-attributed sales: your 20.0% ACoS is at or below your 35.0% break-even.
Amazon ACoS — frequently asked questions
- How do you calculate ACoS?
- ACoS (Advertising Cost of Sale) = Ad Spend ÷ Ad-Attributed Sales × 100. If you spent $300 on ads that generated $1,500 in attributed sales, your ACoS is 300 ÷ 1500 = 20%. It tells you how many cents of advertising it took to earn a dollar of ad-attributed revenue.
- What is a good ACoS on Amazon?
- A "good" ACoS is below your break-even ACoS, which equals your unit profit margin. If a product has a 35% margin after fees and COGS, any ACoS under 35% is profitable on the ad-attributed sale alone. Below that you make money; above it you need TACoS-level analysis to know whether organic lift keeps the campaign net positive.
- What is the difference between ACoS and ROAS?
- They are inverses of the same relationship. ACoS = Ad Spend ÷ Ad Sales (lower is better). ROAS (Return on Ad Spend) = Ad Sales ÷ Ad Spend (higher is better). A 20% ACoS is the same as a 5.0x ROAS.
- What is break-even ACoS?
- Break-even ACoS is the ACoS at which an ad-attributed sale earns zero profit — it equals your unit profit margin percentage. Knowing it tells you the ceiling for bidding before a campaign loses money on the ad-attributed revenue.