ACoS Calculator
Enter your ad spend, ad sales and profit per unit before ads. You get your ACoS, the ACoS at which ads stop being profitable, and the CPC you can afford.
How it works
Amazon Ads defines ACoS (advertising cost of sales) as ad spend divided by the sales attributed to those ads. ROAS is the inverse: sales divided by spend.
Break-even ACoS is your profit per unit before ads divided by the selling price. If you keep $9 on a $29.99 product before ads, break-even ACoS is 30%: above that, ad-driven sales lose money. TACoS divides ad spend by all sales, including organic ones.
Fees used (official sources)
- ACoS definition: ACOS = ad spend ÷ ad revenue (e.g. $50 spent for $100 in sales = 50%). Source: advertising.amazon.com (checked 2026-10-29)
Numbers you enter yourself
We only pre-fill rates we could confirm on the platform's own page on 2026-10-29. These depend on your product or account, or could not be verified, so the calculator asks you for them:
- Profit per unit before ads – depends on your referral and FBA fees; get it from the Amazon FBA fee calculator. Source: sell.amazon.com (checked 2026-10-29)
Frequently asked questions
How is ACoS calculated?
ACoS = ad spend ÷ ad-attributed sales × 100%. Amazon's own example: spending $50 to make $100 in sales is an ACoS of 50%.
What is break-even ACoS?
Your profit margin before advertising: profit per unit before ads ÷ selling price. An ACoS at that level means the ad spend uses up all of your profit.
What is the difference between ACoS and TACoS?
ACoS divides ad spend by ad-attributed sales only. TACoS divides ad spend by total sales, including organic, and shows how dependent the whole product is on ads.
How do I convert ACoS to ROAS?
ROAS = 1 ÷ ACoS. An ACoS of 25% equals a ROAS of 4.