# ACoS Calculator

URL: https://aiadking.com/tools/acos-calculator
Updated: 2026-09-03

Free Amazon ACoS calculator: enter ad spend and ad sales to see your ACoS and ROAS instantly, plus how AIAdKing lowers ACoS automatically.

ACoS (Advertising Cost of Sales) is your ad spend divided by the sales those ads produced, as a percentage: ACoS = (ad spend ÷ ad sales) × 100. For example, $22 of spend that drives $111 in sales is a 20% ACoS — the same as a 5.0 ROAS. A lower ACoS means your ads worked harder for each dollar.

## FAQ

Q: How do you calculate ACoS?
A: ACoS (Advertising Cost of Sales) is your ad spend divided by the sales those ads generated, shown as a percentage: ACoS = (ad spend ÷ ad sales) × 100. If you spent $22 on ads that produced $111 in sales, your ACoS is 20%. A lower ACoS means each dollar of ad spend brought in more sales.

Q: What is the difference between ACoS and ROAS?
A: They are two views of the same numbers. ACoS is spend ÷ sales (lower is better); ROAS (Return on Ad Spend) is sales ÷ spend (higher is better). A 20% ACoS is the same as a 5.0 ROAS. This calculator shows both so you can use whichever your team prefers.

Q: What is a good ACoS on Amazon?
A: A good ACoS is any figure below your break-even ACoS — the point where an advertised sale still makes a profit after product cost and fees. That break-even depends on your margins, so there is no single universal number. Sellers with high margins can run a higher ACoS profitably; thin-margin products need a lower one.

Q: Does this calculator store my numbers?
A: The calculation itself runs in your browser and the values you type are not sent back to our servers or saved to any account. Standard analytics cookies (which never see the numbers you enter) still record that you visited the page. It is a quick reference tool, not connected to your Amazon account.

Q: How does AIAdKing help lower ACoS?
A: AIAdKing harvests negative keywords, trims bids on losing targets and shifts budget toward what converts, every night on the official Amazon Ads API — each change logged with a reason and previewable in shadow mode. It is a flat $29/month with no commission on ad spend. See the lower-ACoS page for the full method.