Enter ad spend and attributed revenue. Get ROAS, ACoS, break-even ACoS from your product margin, and net ad profit — so you know whether the ads are actually making money.
Updated Sep 26, 2025 · sources on every number
ROAS & ACoS calculator
Live · 2026
What your ads cost over the period.
Sales your ad platform attributes to the campaigns.
Gross profit margin, in % — unlocks break-even ACoS.
Result
ROAS & ACoS
Return on ad spend
4.0×
ACoS is at or below break-even — the campaign is profitable.
Break-even ROAS: 3.3×
ROAS = revenue ÷ spend. ACoS = spend ÷ revenue.
Source:Amazon Ads · ads-math· Sep 26, 2025
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Ad spend and attributed revenue from your ad platform, for the same period.
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Gross profit margin turns the raw ratio into a verdict you can act on.
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ROAS as a multiple of spend, ACoS as a percentage of revenue — the same fact twice.
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Below break-even ACoS you keep money; above it every ad dollar loses some.
They're the same relationship from two sides. ROAS is revenue ÷ ad spend — how many dollars of sales each ad dollar brings in. ACoS is ad spend ÷ revenue — what percent of your attributed sales went to ads. A ROAS of 4.0× is an ACoS of 25%.
The ACoS at which your ad revenue exactly covers your product margin — in other words, your gross profit margin itself. If your margin is 30%, break-even ACoS is 30% and break-even ROAS is 3.33×. Below break-even ACoS you profit from every ad dollar; above it you lose money on ads even when they generate sales.
There's no universal number — a profitable one depends on your margin. Amazon Ads defines break-even ROAS as 1 ÷ gross profit margin. A 40% margin means break-even ROAS of 2.5×: anything above that is profitable for you, regardless of what other sellers call 'good'.
Sales your ad platform credits to your campaigns within its attribution window (Amazon and Google Ads default to 7 days of clicks, 14 for views). Attributed revenue is the number to pair with spend from the same platform — mixing numbers from different periods or sources inflates or hides performance.
Yes. The formulas and break-even definition follow Amazon Ads' official ads-math guide, updated September 26, 2025, which is linked in the calculator. Attribution windows are platform settings, so your ad platform's own reporting is the source of the inputs.
Referral, fulfillment, storage and placement — the full 2026 schedule.
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Final value fees, category by category, with the $0.30–$0.40 per-order fee.
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Transaction, processing, listing and offsite ads — broken down line by line, by country.
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