Amazon ACoS calculator

ACoS (advertising cost of sales) is the share of your Amazon ad sales that you spent on ads. An ACoS of 25% means you paid $25 in ads for every $100 of sales your ads brought in.

Divide your ad spend by your ad sales and multiply by 100. Use the same campaigns and the same dates for both numbers. $250 in ad spend that brings in $1,000 in ad sales is a 25% ACoS.

ACoS = ad spend / ad sales x 100. Ad sales are the sales Amazon attributes to your ads: 7 days after a click for Sponsored Products, 14 days for Sponsored Brands and Sponsored Display.

A good ACoS is one below your break-even ACoS, which equals your profit margin before ads. With a 40% margin, any ACoS under 40% makes money on ad sales. Across the 66 Amazon ad accounts in our September 2026 benchmarks, the median ACoS was 34.2%.

Break-even ACoS is the highest ACoS you can run before ads stop making money. It equals your profit margin before ads. Example: a $100 product with $30 in Amazon fees and $30 in product cost has a 40% margin, so its break-even ACoS is 40%.

Target ACoS is the ACoS you choose for a goal. For a product launch or ranking push you might accept an ACoS above break-even for a few weeks. For steady profit you set it well below break-even, so there is margin left after ads.

They use the same two numbers, turned around. ACoS = ad spend / ad sales x 100 and ROAS = ad sales / ad spend. A 25% ACoS is a ROAS of 4.0 and a 50% ACoS is a ROAS of 2.0. Amazon reports ACoS, while Google and Meta usually report ROAS.

ACoS compares ad spend with ad sales only. TACoS compares ad spend with all sales, ad and organic. If TACoS falls while ACoS stays flat, your ads are helping organic sales grow.