◆ Free calculator
Amazon FBA calculator
Enter your sale price, COGS, inbound shipping, FBA fulfilment fee and referral percent to see net profit, margin and break-even ACoS — updating live as you type. No signup.
Calculate your unit economics
The arithmetic
How to read the results
- 1
Net profit
Revenue minus the Amazon referral fee, the FBA fulfilment fee, COGS plus inbound shipping, and any overhead you entered. Each line is rounded to the cent before it is summed, so the numbers on screen add up exactly.
- 2
Margin
Net profit divided by revenue, shown as a percentage of the sale price.
- 3
Break-even ACoS
Equal to the margin, by definition — advertising eats profit dollar for dollar. Spend less than this share of revenue on PPC and you keep some profit; spend more and the ads eat the product.
Fees are inputs, not assumptions. The referral percentage and the fulfilment fee both depend on your category and size tier and Amazon revises them, so this tool asks for the figures on your own listing instead of printing a fee table that would silently go out of date.
FBA calculator FAQ
The questions sellers ask before they trust a margin number.
Ask us something elseBreak-even ACoS is the share of revenue you can spend on Amazon advertising before the product stops being profitable. If your margin is 27%, you can spend up to 27% of revenue on ads before losing money.
It supports an optional per-unit overhead input to approximate returns, storage, or amortised costs. Leave it at 0 for a pure contribution-margin view.
Most Amazon categories use 15%. Some accessories, jewellery, and media categories use different tiers — check Amazon Seller Central for your specific category.
From you. The fulfilment fee depends on the size tier and weight of your unit and Amazon revises it, so the calculator asks for the figure on your own listing rather than shipping a fee table that would quietly go stale.
Once the numbers work, trim the fixed costs
A point of margin bought by cutting software is a point you keep at every unit volume.