Calculate Advertising Cost of Sale for Amazon Ads campaigns. Optimize your AMS spend and improve campaign profitability.
ACOS is Amazon's primary advertising metric. Lower is better - it shows what percentage of sales goes to advertising.
Compare ACOS to your profit margin. If ACOS is lower than your margin, your ads are profitable.
Track ACOS by keyword, product, and campaign to identify winners and pause losers quickly.
ACOS (Advertising Cost of Sale) is the percentage of sales revenue spent on advertising. For example, 25% ACOS means you spend $0.25 on ads for every dollar of sales. It's the inverse of ROAS.
For KDP books with 70% royalty, a good ACOS is typically below 30-35%. This ensures your ads are profitable after Amazon's cut. Lower ACOS means more efficient advertising.
Target ACOS varies by goal: aim for 15-25% for profitability, 30-40% for visibility, or accept higher ACOS during launches to build momentum.
For KDP books, 20-30% ACOS is good, 15-20% is excellent. Your target depends on profit margins and goals. Never exceed your profit margin or you lose money per sale.
ACOS = Ad Spend ÷ Sales. ROAS = Sales ÷ Ad Spend. They're inverses. 25% ACOS = 4:1 ROAS. Amazon uses ACOS, most other platforms use ROAS.
ACOS over 100% means you spend more on ads than you earn in sales - a loss. Pause the campaign and review targeting, keywords, and ad creative.
Calculate Return on Ad Spend - the inverse metric of ACOS.
Calculate your profit margin to set target ACOS correctly.
Determine how many ad-driven sales needed to profit.