ACoS calculator: work out your Amazon ACoS
ACoS (advertising cost of sales) is your Amazon ad spend divided by the sales those ads generated, shown as a percentage. Enter ad spend and ad sales in the calculator to get ACoS and ROAS, then compare ACoS with your profit margin before ad costs to see whether your advertising is profitable.
- ACoS and ROAS instantly
- Compare with break-even ACoS
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Break-even ACoS calculator
Enter one product’s numbers. Everything updates as you type.
How is ACoS calculated?
ACoS = ad spend ÷ ad sales × 100. If you spend £100 on ads and those ads generate £500 in sales, your ACoS is 20%.
ROAS is the same relationship turned around: ROAS = ad sales ÷ ad spend. A 20% ACoS equals a 5x ROAS. Both figures come from the Amazon Ads console, so make sure you use the same date range and attribution window for spend and sales.
What do you enter in the calculator?
| Input | Where to find it | Notes |
|---|---|---|
| Ad spend | Amazon Ads console, campaign manager | Use the same date range as ad sales |
| Ad sales | Amazon Ads console, sales column | Attributed sales, not total sales |
| Profit margin before ad costs (optional) | Your own cost data or a profit tool | Selling price minus product, shipping and Amazon fees, as a % |
What does a worked example look like?
Example: you spend £1,000 on Sponsored Products in a month and the ads generate £5,000 in sales. ACoS = £1,000 ÷ £5,000 × 100 = 20%. ROAS = £5,000 ÷ £1,000 = 5x.
Example: your margin before ad costs is 30%. That is your break-even ACoS. At 20% ACoS you keep roughly 10% of each ad-driven sale as profit. At 35% ACoS you would be losing money on every ad-driven sale, before counting any organic lift.
How should you read your result?
| Your ACoS compared with margin | What it means | What to consider |
|---|---|---|
| Well below break-even | Ads are profitable per sale | Room to bid harder on converting terms |
| Close to break-even | Ads roughly pay for themselves | Fine for launches or ranking pushes, not forever |
| Above break-even | Each ad sale loses money | Cut wasted search terms, fix listings, lower bids |
What should you do after calculating ACoS?
- Work out ACoS by product line, not just account-wide
- Check which search terms spend without converting
- Compare ACoS with TACoS using the TACoS calculator
- Review whether listings match your converting queries
- Read how to lower ACoS for practical fixes
A low ACoS is not always the goal
ACoS only measures ad-attributed sales. If ads lift organic rank, a higher ACoS can still grow total profit. That is why we judge accounts on TACoS and margin too. See ACoS vs TACoS.
Common questions
Short, direct answers. Ask us anything else on a free audit call.
What is a good ACoS on Amazon?
A good ACoS is one below your break-even ACoS, which is your profit margin before ad costs. There is no single number that suits every product.
How do I calculate break-even ACoS?
Take your selling price, subtract product cost, shipping and Amazon fees, and divide the result by the selling price. That percentage is your break-even ACoS.
What is the difference between ACoS and ROAS?
They are the same data inverted. ACoS is spend divided by sales as a percentage, and ROAS is sales divided by spend as a multiple.
Should I calculate ACoS per product or per account?
Per product line where you can. Account-wide ACoS hides lines that lose money behind lines that do well.
Why is my ACoS different in different reports?
Different date ranges and attribution windows give different figures. Use the same range and attribution for spend and sales.
Keep reading
ACoS vs TACoS
ACoS measures ad spend against the sales your ads directly generated; TACoS measures ad spend against all your sales, paid and organic.
How to lower ACoS
To lower ACoS, cut search terms that spend without selling, set bids from a target ACoS instead of guessing, move budget to placements and keywords that convert, and improve the listing so more clicks become orders.
TACoS calculator
TACoS (total advertising cost of sales) is your Amazon ad spend divided by your total sales, paid and organic, shown as a percentage.
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