Amazon Break-Even ACoS & Max Bid Calculator.
Free Amazon ACoS calculator: enter price, product cost, Amazon fees, and conversion rate to get your break-even ACoS and the maximum CPC you can profitably bid. Runs in your browser.
What this calculator does
Enter your sale price, product cost (COGS), Amazon referral fee, FBA fee, and conversion rate. It returns your break-even ACoS — the advertising cost of sale where ad profit is zero — your net profit per unit, and the maximum CPC you can profitably bid, with a table of max bids by target ACoS.
How break-even ACoS is calculated
Break-even ACoS equals your contribution margin as a percentage of price: sale price minus COGS, Amazon referral fee, and FBA fee, divided by price. Spend below it and each ad-driven sale is profitable; spend above it and you lose money on every order.
How the maximum bid is calculated
Revenue per click equals price times conversion rate, so the most you can profitably pay per click is target ACoS times price times conversion rate. Bid at break-even for maximum volume, or below it to keep profit on every sale.
Why it matters
A 35 percent account-wide ACoS is not fine if the products carrying it have a break-even ACoS in the low 20s. This calculator shows the line per product so you stop bidding into losses.
Frequently asked questions
What is break-even ACoS on Amazon?
Break-even ACoS is the advertising cost of sale at which ad profit is exactly zero — it equals your contribution margin as a percentage of price (sale price minus COGS, Amazon referral fee, and FBA fee, divided by price).
How do you calculate the maximum CPC bid?
Maximum profitable CPC equals target ACoS times sale price times conversion rate. At break-even ACoS this is the most you can pay per click without losing money; a lower target ACoS leaves profit on every sale.