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ACoS

Advertising cost of sales

Amazon ad spend as a percentage of the revenue those ads produced.

ACoS (advertising cost of sales) is Amazon ad spend divided by ad-attributed revenue, as a percentage. A 25% ACoS means you spent $0.25 in ads for every $1 of ad-driven sales. It's the standard measure of Amazon campaign efficiency — the inverse of ROAS.

Formula

ACoS = Ad spend ÷ Ad revenue × 100

Example: $3,000 spend on $12,000 ad revenue = 25% ACoS.

What a good result depends on

A ‘good’ ACoS is at or below your break-even ACoS (set by your margin); launches run higher on purpose.

Common mistakes

  • Chasing a low ACoS at the expense of total sales — that's what TACoS catches.
  • Comparing ACoS across products with different margins.
Free calculator
Amazon TACoS Calculator
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