Amazon FBA Profit Calculator

Why Amazon Margin Math Is Not Obvious

Amazon FBA sellers quote gross margins that rarely match their bank deposits. The gap is fees. Three fee streams hit every FBA sale: the referral fee (a percentage of selling price, most commonly 15%), the FBA fulfilment fee (a flat per-unit amount set by weight and dimensions), and the monthly storage fee (charged on volume, and higher in the fourth quarter when inventory sits pre-holiday). A product selling for 30 with a 10 product cost shows a 67% gross margin. After 4.50 referral, 4 fulfilment and 0.50 storage, the net margin is about 37%.

Referral Fee Percentages by Category

The figures in this section describe Amazon's United States marketplace schedule. Other marketplaces publish their own percentages, thresholds and currencies, so a seller outside the US should read the equivalent table in their own Seller Central account. Most categories are charged 15% of selling price. Personal Computers sit at 6% and Consumer Electronics at 8%, while Gift Cards and Jewellery sit at 20%, and Amazon Devices sit at 45%. Books carry 15% plus a fixed closing fee. Grocery ranges between 8% and 15% depending on price point. Most categories also carry a minimum referral fee per unit. The percentage itself takes the same share at every price, so it is that floor which makes very low-priced items give up an outsized share of revenue: once the minimum exceeds the percentage, the effective rate climbs as the price falls. These figures change over time and Seller Central lists the current schedule. The calculator takes the referral percentage as a direct input, so you can enter the rate that applies to your own category and marketplace.

FBA Fulfilment Fee Brackets

Amazon sets the fulfilment fee from the item's size tier and shipping weight. In the US schedule, small standard units are charged roughly 3 to 4 per unit, large standard units roughly 4 to 5, and oversized units anywhere from 9 to 35 depending on exact dimensions and weight. Apparel is charged on a separate tier. Non-US marketplaces band by grams and kilograms rather than pounds, and by cubic metres rather than cubic feet, so the bracket names do not transfer directly. Amazon revises these fees once or twice a year. The calculator takes the fulfilment fee as a direct per-unit input, so it adapts to whatever bracket your product falls into.

Costs That Sit Outside This Calculator

Several real FBA costs are not part of the per-unit math above. Amazon charges a returns processing fee on returned orders, which varies by category. Inventory older than 365 days attracts a long-term storage fee, and removal or disposal of slow-moving stock is charged separately. Advertising is a separate line entirely: Amazon PPC commonly runs at 10% to 15% of revenue on an active campaign. A Professional selling plan carries a fixed monthly subscription. Profits are taxed. Because all of these sit outside the calculation, the amount that reaches a bank account is lower than the net profit shown here. Inbound shipping is the one exception on this page: it varies with freight method, lane and unit density, and it belongs inside the landed product cost input above rather than outside the model.

Worked Example

Take a reusable water bottle selling at 24.99, with a landed product cost of 6 including inbound shipping. The referral fee at 15% is 3.7485. The FBA fulfilment fee is 4.75. Monthly storage costs 300 across 800 units sold, so the allocated storage is 0.375 per unit. Profit per unit is 24.99 - 6 - 3.7485 - 4.75 - 0.375 = 10.1165, which displays as 10.12. Monthly profit is 10.1165 × 800 = 8,093.20, and the net margin is 40.48%. Adding 2,000 a month of Amazon PPC brings monthly profit to about 6,093.

Where the Per-Unit Math Leaves Little Room

Low selling prices compress FBA margins quickly, because the fixed elements do not shrink with the price: the flat fulfilment fee, the minimum referral fee once it binds, and the landed product cost. The referral percentage is the one component that scales with price, so it takes the same share at every level. Oversized items carry the highest fulfilment fees and need a wide gross margin to absorb them. Seasonal stock that sits through the fourth quarter is charged the higher peak storage rate, and inventory that ages past a year attracts long-term storage fees on top. The calculator models a single month at the rates you enter, so a product whose costs vary across the year will read differently month to month.