FBA Fees Explained: What Amazon Charges for Fulfillment
July 17, 2026
FBA fees are the charges Amazon applies for storing, packing, and shipping your products when you use its logistics service (Fulfillment by Amazon). At the core there are two big blocks: the fulfillment fee —what Amazon charges to pick your product, pack it, and deliver it to the buyer, calculated from the weight and size of each unit— and the storage fee, charged for the space your inventory occupies in Amazon’s warehouse while it waits to sell. On top of those two come extra charges for oversized items, for inventory that sits too long, and for returns. All of it comes out of your margin before you ever see a cent of profit.
The reason so many sellers get FBA wrong isn’t that the fees are high —they’re often cheaper than building your own logistics from scratch— but that there are several of them, they change by category, weight, and season, and they never appear together in one place. You see the sales commission in one report, the fulfillment fee in another, storage as a separate monthly charge, and by the time you’ve stitched it all into a spreadsheet the month is over and the number you thought was your profit was actually half of it.
This article takes FBA fees apart piece by piece: exactly what Amazon charges, how each fee is calculated, where the most painful ones hide, and how to know whether a product is still profitable after subtracting everything. The goal isn’t to memorize rates —those change— but to understand the structure so no charge catches you by surprise.
the fulfillment fee: the main charge
The largest and most consistent FBA fee is the fulfillment fee. It’s what Amazon charges for every unit it sells: pulling the product from its warehouse, packing it, applying the shipping label, and delivering it to the buyer’s door. It’s charged per unit sold, not per month, so you only pay when you actually sell.
What matters is how it’s calculated: it depends on your product’s weight and dimensions, not its price. Amazon classifies every item into a size tier —small standard, large standard, oversize— and within that tier charges by weight. This has a consequence that confuses many new sellers: two products that sell at the same price can carry very different fees if one is light and compact and the other is heavy or bulky. A small $30 accessory can leave you far more margin than a large, heavy $30 product, even though the price tag reads the same.
Here’s a technical detail that costs money: dimensional weight. Amazon doesn’t always charge by the scale weight. If your product is large but light —a pillow, a foam box— it calculates a “dimensional weight” from the volume of the package and charges on the greater of the two. A lightweight product that takes up a lot of space can cost as much to ship as a heavy one, and that completely changes the profitability of entire categories.
Glossary: real net margin, with commission, fees, and shipping already subtracted →storage: the fee that runs whether you sell or not
The second block is the storage fee, and it’s different in nature: it’s charged for the space (measured in cubic feet) your inventory occupies in Amazon’s warehouse, every month, whether it sells or not. Unlike the fulfillment fee, this charge runs in the background even when the product sits still. It’s the cost of holding stock that’s waiting.
Standard monthly storage rises sharply in the last quarter of the year —October, November, and December— because warehouse space is scarce right before peak season. Inventory that was cheap to hold in summer can triple its storage cost in November. That’s why shipping in too much product “just in case” before Black Friday or the holidays can eat your margin during the very months you sell the most.
And there’s a charge that specifically penalizes sleeping inventory: the aged inventory or long-term storage fee. When a product has been in the warehouse too long without selling, Amazon adds a surcharge per cubic foot on top of normal storage. It’s their way of pushing you not to pile up product that doesn’t move. For a seller who ships large lots hoping to sell them “eventually,” this fee is a silent trap: it doesn’t show up on each sale, it shows up in a monthly charge many never even review.
Glossary: what a price calendar is and how to move inventory before storage costs rise →the referral fee: not FBA, but it adds up
It’s worth separating a charge that gets confused with FBA fees but is distinct: the referral fee. Amazon charges this for selling on its marketplace, whether you use FBA or ship the product yourself. It’s a percentage of the sale price and varies by category —usually somewhere between 8% and 15% depending on the product type.
The confusion matters because when you calculate a FBA product’s profitability you have to add both: the referral fee (a percentage of the price) plus the fulfillment and storage fees (fixed amounts based on weight and volume). A seller who only subtracts the commission and forgets the logistics believes they earn twice what they actually do. A seller who subtracts everything but at the wrong per-channel price doesn’t have the real number either. That’s why the starting point is always the same question: how much is left after absolutely everything?
Glossary: what a tiered offer is and how to protect margin when moving prices →the fees you don’t see until the charge lands
Beyond the three big ones —fulfillment, storage, and commission— FBA has a list of secondary charges that don’t show up on a normal sale but hit when you least expect them:
- Returns. In categories with free returns, Amazon processes the return and in many cases that product can no longer be resold as new. You lose the unit, the commission isn’t always fully refunded, and sometimes you pay a return-processing fee.
- Removal or disposal of inventory. If you decide to pull product from the warehouse —because it isn’t moving, or to avoid the aged-inventory fee— Amazon charges per unit removed or destroyed.
- Labeling and prep. If you ship product that doesn’t arrive ready by their rules (no barcode, no bag, no protection), Amazon preps it and charges you the service per unit.
- Peak-season surcharges. In the busiest months, some fulfillment fees rise with a temporary surcharge many sellers don’t factor into their September math.
None of these appear when you calculate the margin on a happy sale. They appear in different reports, on different dates, and that scatter is exactly what makes a seller believe they earn more than they do.
why stitching fees together by hand costs you
The underlying problem isn’t that FBA has many fees, it’s that they live apart. The commission shows up in the transaction report, the fulfillment fee in each order’s detail, storage in a monthly charge, aged inventory in another, returns in a separate adjustment. And if you also sell on MercadoLibre and move stock through a 3PL, you have three different cost structures for the same product across three different tabs.
So the most basic question —“does this SKU actually make me money?”— gets answered at month-end, copying figures into a spreadsheet that’s never up to date. By the time you’ve built the number, you’ve already sold for weeks at a margin you thought was good and wasn’t. As we cover in minimum profitable price: how to calculate your selling floor, your real price floor doesn’t exist until you subtract all the fees, and that floor is different on each channel.
The alternative is to see real net margin by SKU and by channel, with every FBA fee already subtracted, in real time and in a single panel —not rebuilt by hand when it’s already too late. When you see the effect of fulfillment and storage on profit at the same moment you set a price or schedule a promotion, the month-end charge stops surprising you. And that same figure is what you need to read your advertising correctly: as we explain in what is ACoS, an ad spend that looks reasonable can turn into a loss if the FBA fee already ate the margin you’re bidding on.
Understanding FBA fees isn’t about memorizing a rate table Amazon changes every season. It’s about understanding the structure —fulfillment by weight and volume, storage by space and time, commission per sale, plus the hidden charges— and having the final number in view before you decide. That’s the difference between a product you think is profitable and one that truly is. A store like SPORTIFY selling across several channels only defends its margin when it sees the full cost of each unit, not half of it.