Free Amazon ACoS calculator
Calculate break-even ACoS, then protect profit with a stricter target ACoS.
Enter your actual selling price and per-order costs. CEILR calculates pre-ad contribution, allowable advertising spend per order, the corresponding ACoS ceiling and—if you enter conversion rate—an optional CPC ceiling.
Amazon ACoS formula
Break-even ACoS is a boundary, not automatically a good operating target.
Pre-ad contribution = selling price − landed cost − Amazon/per-order fees − other per-order costs. Allowable ad spend/order = pre-ad contribution − protected contribution. ACoS ceiling = allowable ad spend/order ÷ selling price.
Break-even ACoS vs target ACoS
If protected contribution is zero, the result is a simple break-even ACoS based on the order-level costs you entered. In that simplified model, spending at that ratio consumes all represented pre-ad contribution.
Enter a protected contribution amount to calculate a stricter target ACoS ceiling that preserves some contribution after advertising.
Optional CPC ceiling = allowable ad spend/order × conversion rate. This connects the ACoS boundary to a per-click economic ceiling.
This calculator uses only seller-entered values. It does not retrieve Amazon fees, ad performance or conversion data and does not predict sales.
Worked Amazon ACoS example
Break-even and profit-protected ACoS are not the same number.
The following values are hypothetical and demonstrate only the formulas. They are not Amazon fee estimates or recommended targets.
| Input / result | Example | Calculation |
|---|---|---|
| Selling price | $44.95 | Seller-entered |
| Pre-ad contribution | $17.45 | After entered costs |
| Break-even ACoS | 38.82% | $17.45 ÷ $44.95 |
| Protected contribution | $5.00 | Seller wants this left after ads |
| Allowable ad spend | $12.45 | $17.45 − $5.00 |
| Profit-protected ACoS ceiling | 27.70% | $12.45 ÷ $44.95 |
| At 10% CVR: CPC ceiling | $1.25 | $12.45 × 10% |
Amazon ACoS questions
“Good ACoS” depends on the economics of the product—not a universal benchmark.
The same 25% ACoS can be comfortably profitable for one ASIN and loss-making for another because landed cost, Amazon fees and contribution differ.
Q1What is ACoS on Amazon?
Advertising Cost of Sales.
What is ACoS on Amazon?
Advertising Cost of Sales.ACoS is advertising spend divided by ad-attributed sales, expressed as a percentage. It describes advertising efficiency under the attribution/reporting definition being used; it does not contain product cost by itself.
Q2How do I calculate break-even ACoS?
In this simplified per-order model: pre-ad contribution ÷ selling price.
How do I calculate break-even ACoS?
In this simplified per-order model: pre-ad contribution ÷ selling price.If your pre-ad contribution is $17.45 on a $44.95 sale, the simplified break-even ACoS is about 38.82%. Spending at that boundary leaves no represented contribution after ads.
Q3What is a good ACoS for Amazon PPC?
There is no single correct percentage.
What is a good ACoS for Amazon PPC?
There is no single correct percentage.The appropriate ceiling depends on product contribution, desired profit, lifecycle stage and strategic purpose. A defensive brand campaign and a discovery campaign can also have different roles.
Q4How is ACoS related to max CPC?
Conversion rate translates per-order ad room into a per-click ceiling.
How is ACoS related to max CPC?
Conversion rate translates per-order ad room into a per-click ceiling.Once allowable ad spend per converted order is known, multiply it by conversion rate to estimate the economic CPC ceiling under the assumptions entered.
Continue the PPC decision
Connect ACoS to CPC, TACoS and actual unit economics.
Amazon CPC calculatorTranslate contribution and CVR into a per-click ceiling.
Amazon TACoS calculatorSeparate ad-attributed efficiency from total-sales advertising burden.
Amazon profit margin calculatorSee pre-ad and post-ad contribution directly.
Embed this calculator freePut the Profit-Safe CPC calculator on your own site.
CEILR remains read-only to Amazon seller state and does not change campaigns, bids, budgets or keywords for the seller.
Connect the ceiling