What the Amazon calculator includes
The Amazon FBA calculator adds up three charges: the referral fee, the FBA fulfillment fee and the monthly storage fee, and then shows your estimated net profit per unit. Referral fees depend on the product category and are commonly 8 to 17 percent, with 15 percent a typical default. Fulfillment fees depend on the size tier of the item, from small standard up to oversize, and storage is charged per cubic foot, at a higher rate from October to December.
Reading the result
The result is only as good as the numbers you enter. Your product cost, the cost of getting inventory to Amazon, returns and any advertising are specific to you, so add them yourself before treating the profit figure as real. Because size and weight decide the fulfillment tier, measure your packaged item carefully.
Confirming the exact fee
Amazon updates its fee schedules often and calculates them from exact dimensions. This page uses published rates and says so, but for a specific product use Amazon’s own revenue calculator before you commit to buying inventory. Our how we calculate page explains the method and the disclaimer covers the limits.
What to compare
The same product can look very different at different sizes and weights, so run the calculator for the exact packaged dimensions and weight, and try it at your category’s referral rate and at a more conservative one. If the profit disappears at the higher fee level, the product has little margin to spare. The Amazon calculator sits alongside the marketplace calculators, so you can compare what the same item would net elsewhere. Treat the result as a first filter: a product that only works on a very thin margin is rarely worth the risk once real-world costs are added.