Amazon's fee structure is the most complex of any major marketplace, which is exactly why so many sellers misprice. There are three core fees every FBA seller pays, plus a long tail of situational ones that most free calculators quietly ignore. Here is the full picture.
1. Referral fees: Amazon's commission
Most categories charge 15% of the total sales price (including shipping), up to a per-item maximum. Some categories differ: electronics are typically lower, while clothing uses tiered rates. This fee applies whether you fulfill yourself or use FBA.
2. FBA fulfillment fees: pick, pack, and ship
This is what you pay Amazon to handle logistics, charged per unit based on size tier and weight. A small standard-size item costs a few dollars to fulfill; oversize items climb steeply. Weight bands matter enormously: shaving an ounce can drop you into a cheaper tier, which is why experienced sellers obsess over packaging.
3. Monthly storage fees: rent for your inventory
Charged per cubic foot per month, with higher rates in Q4 (October through December). Slow-moving inventory gets expensive fast, and aged inventory surcharges kick in for stock sitting over 180 days. Storage fees punish over-ordering, which is why inventory turnover is a core FBA skill.
The fees most calculators miss
Inbound placement fees, low-inventory-level fees, returns processing, and removal or disposal orders all come out of the same pocket. Industry analyses suggest basic calculators understate true per-unit cost by $0.70 to $1.30. Model these before you commit to a product, not after your first payout disappoints you.
A real example
Sell a $25 kitchen gadget (standard size, under a pound). Referral fee: about $3.75. FBA fulfillment: roughly $3 to $4 depending on exact dimensions. Storage: a few cents per month per unit. Amazon fees total around $7 to $8 before product cost, inbound shipping, and advertising. Plug your exact numbers into our free Amazon profit calculator to see your true margin per unit.
Amazon adjusts fees annually, usually in the spring. Verify the current schedule in Seller Central before making sourcing decisions.