Amazon FBA Fee Stack & Unit Margin — What a unit keeps after referral, fulfillment, storage and the size tier
A $24.99 unit on $6.00 of goods keeps $10.39, not the $18.99 that price-minus-cost suggests — and an ounce over a pound costs you $0.46 of it.
What the year has to bring in
The first worksheet page starts from $50,000 of take-home income, $15,600 of overhead across the items listed and tax on profit, and works out the revenue the business needs: $82,266.67 a year. This business does not sell hours, so the kit does not turn that into an hourly rate. Every step is printed, with a blank worksheet for your own numbers.
Price minus cost is not the margin
A $24.99 unit on $6.00 of landed goods, 14 oz packed in an 8 x 6 x 2 in box, keeps $10.39 off-peak, not the $18.99 that price-minus-cost suggests: a 41.6% margin once the referral fee, the fulfillment fee (with Amazon's 3.5% surcharge) and monthly storage are counted. On the holiday card it keeps $9.91.
Weight is a staircase rather than a slope: an ounce over a pound adds $0.46 a unit to the fulfillment fee, $4,600 a year on ten thousand units. The size tier depends on the box dimensions as well as the weight, and since 2026 the fee also depends on the price band (under $10, $10-$50, over $50).
Because the referral fee is a share of price, you cannot mark cost up to a target margin. A 25% margin on that unit needs a $18.08 list price; marking cost up gives $8.
This is a fee-and-margin tool, not a sourcing course. Fees are Amazon's US standard-size rates checked October 13, 2026 (off-peak and holiday cards, price bands, surcharge, storage); Amazon changes them, so confirm on Seller Central. The live Excel workbook works out the size tier from your packed weight and box dimensions and looks the fee up from the rate card, so changing either changes the fee. All 22 formulas verified by recalculation.
8 client scripts
Each one carries a line explaining why it is worded that way, because a script you do not understand is one you will not send. Placeholders are in [BRACKETS] so nothing goes out in someone else's words.
- Asking a supplier for a dimensional and weight spec
- Negotiating unit cost against a bigger order
- The supplier whose sample differs from the production run
- Challenging an incorrect FBA fee classification
- Responding to a negative review that misstates the product
- Declining a bundle request that changes the size tier
- Telling a supplier a shipment failed inspection
- Raising a price when fees change
What this is not
These numbers are not a market price. They are arithmetic about you — what your income target requires. They do not tell you what your market will pay. If the number is far above what your market bears, that is real information: something has to move, and quietly working below the floor is the one option that cannot last.
These are scripts, not contracts, and nothing here is legal or tax advice. No script threatens statutory interest, collections or legal action — whether any of those is available to you depends on your contract and jurisdiction. The 25% tax figure is a placeholder; ask your accountant for yours.
Honest about the format
Printable PDFs plus an editable Excel workbook, not a physical product. One US Letter PDF (13 pages) and one A4 PDF (13 pages), and one .xlsx that opens in Excel, Numbers, LibreOffice and Google Sheets. Files are available immediately after purchase; nothing ships.
Refunds
If this isn't what you expected, email me within 30 days and I'll refund you in full — no need to explain. Because it's an instant download I can't take the files back, so I'd rather you just had your money back.