Free tools

Calculators that show their working.

Short answer

Three free calculators for sellers pricing real inventory: profit margin and markup on any product, Amazon FBA profit after referral and fulfillment fees, and dropshipping profit with the break-even ROAS your campaigns have to beat. No signup, and every formula is written out on the page.

The calculators

Profit margin calculatorGross margin, net margin, markup and ROI on any product, plus the price that hits a target margin.Amazon FBA profit calculatorFBA profit, margin, ROI and break-even ACoS after referral fees, fulfillment, storage, ads and returns.Dropshipping profit calculatorProfit per order, margin, ROI and break-even ROAS after product cost, shipping, fees, ads and returns.

Why the arithmetic is written down

Each calculator lists the formula it uses, where its rates came from, and the places where Amazon's own published documentation contradicts itself. Where we had to make an assumption, it is labelled as one.

The Amazon calculator is built on the 2026 US referral fee table and FBA rate cards from Seller Central and sell.amazon.com. Amazon publishes worked fulfillment fee examples for a mobile device case, a t-shirt, an iron, a baby cot, a monitor and a TV, at peak and non-peak rates. The fee engine reproduces ten of those twelve fees to the cent, along with both monthly storage examples. The two it does not match are the t-shirt, where Amazon uses a dimensional weight that its own stated formula does not produce.

These calculators use today's fees.

Notifcentral tells you when Amazon changes a fee on your catalogue, and also alerts you to Buy Box loss, listing suppressions and account health changes on your phone.

Prices and eligible trials are shown by your App Store or Google Play account · cancel anytime

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