Free Amazon ACoS and Max Bid Calculator
Most Amazon sellers know their ACoS but still guess their bids. This free Amazon ACoS calculator turns your price, product cost, fees, and conversion rate into three numbers you can use today: your break-even ACoS, your target ACoS, and the maximum bid you can pay per click and still keep your profit.
Your product numbers
Use real figures from your fee report and ad reports. Everything updates as you type.
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$
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Where each sale goes
Product costAmazon feesAd budget per saleProfit
Max bid at your targetThe most to pay per click and keep your profit.
$0.00
Target ACoSAd spend as a share of ad sales.
0%
Break-even ACoSAbove this, ads lose money.
0%
Break-even max bidThe absolute ceiling per click.
$0.00
Profit before adsPer unit, after cost and fees.
$0.00
Estimates for planning only. Check your real fees in Seller Central, and remember that Amazon's placement adjustments and dynamic bidding can raise your actual cost per click above your set bid.
How the Calculator Works
- Profit before ads is your selling price minus product cost, the referral fee, and fulfillment fees.
- Break-even ACoS is that profit as a share of the price. Spend more than this on ads and every ad sale loses money.
- Target ACoS is break-even ACoS minus the profit you want to keep.
- Max bid is price times target ACoS times your conversion rate. It is the most you can pay per click and still hit your target.
TIP: Conversion rate multiplies your max bid. If you raise conversion from 10% to 15% with better images or reviews, the bid you can afford rises by half, with no change to your ACoS target. That is why listing work and ad work belong together.
For the full explanation with worked examples, read our guides on what a good ACoS is and break-even CPC and max bid. If your current bids are well above your max bid, our PPC audit checklist shows where to look first.
Frequently Asked Questions
How do I calculate break-even ACoS on Amazon?
Subtract product cost, the referral fee, and fulfillment fees from your selling price to get profit before ads. Divide that by the selling price. The result is your break-even ACoS.How do I calculate my maximum bid on Amazon?
Multiply your selling price by your target ACoS, then by your conversion rate. For example, $30 times 30% times 10% gives a maximum bid of $0.90 per click.Why is my actual cost per click higher than my bid?
Placement adjustments and dynamic bidding can raise your actual bid above the base bid you set. Check your campaign settings if costs run higher than expected.What conversion rate should I use?
Use your own recent ad conversion rate for the product: orders divided by clicks from your advertising reports. For a new product with little data, start conservatively and update it as data comes in.Bids above your ceiling?
Get a free PPC audit and we will show you which keywords cost more than they are worth.
