Amazon FBA calculator that works out the size tier and FBA fee from your package, adds the referral fee, storage, ads and product cost, and shows profit per unit, margin, ROI, break-even and monthly profit.
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Every Fulfillment by Amazon sale is split between Amazon, your supplier and you. This Amazon FBA calculator takes your price and your product's packed size and weight, works out Amazon's fees, adds your own costs, and shows what each unit and a month of sales leave you. It needs no ASIN, so a supplier quote and a package size are enough to test an idea before you order stock.
The Amazon fees and costs it counts
Referral fee: Amazon's commission on each sale, a percentage of the total sales price (the item price plus any shipping and gift wrap the buyer pays). The rate depends on the product category, most categories set a minimum fee per item, and media items add a closing fee.
FBA fulfillment fee: a fee per unit for picking, packing and shipping the order. From the packed dimensions and weight, the calculator works out the 2026 size tier, the dimensional and billed shipping weight and the price band, with Low-Price FBA rates under $10. Apparel and dangerous goods have their own rate tables, and a holiday peak switch, set from today's date, applies Amazon's peak rates from October 15 to January 14.
Fuel and logistics surcharge: the percentage Amazon added to fulfillment fees in April 2026 (3.5% at the time of writing).
Monthly storage: charged by the cubic foot of space your stock takes up, at a higher rate from October to December. Set how many months a unit sits in the warehouse, or 0 to leave storage out.
Selling plan: on the Individual plan, Amazon's $0.99 fee on every item sold.
Your costs: product cost, inbound cost per unit (shipping to Amazon plus any inbound placement fee) and ad spend, in dollars or as a percent of the price.
The rate tables are Amazon's published US fees at the time of writing (2026). If Seller Central shows a different fee for your product, type it in: the FBA fee and the referral fee can each be overridden, and the surcharge, months in storage, storage season and selling plan can be changed.
Profit, margin, ROI and break-even
From those inputs the calculator returns your profit per unit, the margin (profit as a share of the price), the ROI (profit as a share of the product cost plus inbound shipping), the break-even price to the cent, and your monthly profit at the number of units you expect to sell. A line-by-line table explains each fee and Amazon's total cut.
A worked example
Say you sell a dog chew toy for $19.99. In this example the category's referral rate is 15%, so the referral fee is $3.00, and the FBA fee for its size, weight and price band is $4.50. The toy costs you $4.25, shipping it to Amazon adds $0.75 a unit, and ads add $2.00 per unit sold. Costs come to $14.50, which leaves $5.49 profit per unit: a 27% margin and an ROI of about 110% ($5.49 earned on the $5.00 it cost to buy and send in). At 300 units a month that is about $1,647 before storage. These numbers are made up to show the math; the calculator uses the rates for your own category, package and price.
What it leaves out
The monthly Professional plan subscription is not counted, and neither are charges that depend on your account or inventory: low-inventory-level fees, returns processing, aged-inventory and storage-utilization surcharges, Overmax and lithium-battery fees, and coupons or deals. If any apply to you, add their share per unit to your product cost.
Enter the selling price and pick the product category to load its referral rate. Then enter the packed length, width and height in inches and the unit weight: the calculator works out the size tier and shipping weight, and from them the FBA fee. Measure the product in its packaging, because that is what Amazon measures. If you already know your FBA fee from Seller Central, type it in and it replaces the estimate.
Add your product cost, your inbound cost per unit and your ad spend. Ads can be a dollar amount or a percent of the price: use your ACoS if every sale comes from ads, or your TACoS for an average. Storage starts at 1 month; set it to 0 to leave it out. Enter the units you expect to sell a month, then read the results:
Profit per unit below zero means each sale loses money. Raise the price, cut ad spend or find a cheaper supplier before you reorder.
Margin: if your usual coupon or deal would push it below zero, keep the product out of that promotion.
ROI helps you choose between products. When cash is tight, the one that turns each dollar of stock into more profit usually wins, as long as it sells.
Break-even is your floor. Never let a repricer or a sale take the price below it.
Amazon fees as a share of the price show how much of each sale Amazon keeps, which is often the surprise on cheap or bulky products.
Run the numbers again whenever Amazon changes its fees, your supplier changes its price or your ad costs move. The calculator runs in your browser for the US store in US dollars, needs no account and has no daily limit.
Frequently asked questions
How do I calculate Amazon FBA fees?
Add the referral fee, which is your category's percentage of the total sales price with a minimum per item in most categories, to the FBA fulfillment fee. That fee depends on the size tier, the shipping weight and the price band, plus the current fuel and logistics surcharge. Then add storage for the months your stock sits in Amazon's warehouses. The calculator works out the tier and weight from your package size and does each step for you.
How do I calculate ROI on Amazon FBA?
Divide the profit per unit by what one unit cost you to buy and send to Amazon (product cost plus inbound shipping), then multiply by 100. A product that costs $4.25, plus $0.75 to ship in, and makes $5.49 profit after fees and ads has an ROI of about 110%.
How much does Amazon take per sale with FBA?
It depends on the category, size, weight and price. The referral fee is a percentage of the price, while the fulfillment fee is a set amount per unit for its size tier, weight and price band. On cheap or bulky products the fulfillment fee takes the bigger share; on expensive, small products the referral fee does. The calculator shows Amazon's total cut as a share of your price.
What is the difference between the referral fee and the FBA fee?
The referral fee is Amazon's commission for selling on its marketplace and applies to every sale, whether Amazon or you ship the order. The FBA fulfillment fee pays Amazon to pick, pack and ship the order, and applies only to FBA units.
Are the fees in the calculator up to date?
The rate tables are Amazon's published US fees at the time of writing (2026), including the holiday peak rates and the fuel and logistics surcharge. Amazon revises its fees from time to time, so you can type your own FBA fee and referral fee per unit and change the surcharge. For a product already in Amazon's catalog, Amazon's own Revenue Calculator in Seller Central shows its exact fees.
What is a good profit margin for Amazon FBA?
There is no single right number. What matters is that the margin stays positive after your usual ad spend, coupons and returns, and leaves enough to pay for the next order of stock. Run the calculator at your planned discount as well as at full price.
Does dimensional weight affect FBA fees?
Yes. For most size tiers Amazon charges on the shipping weight, which is the greater of the product's actual weight and its dimensional weight, worked out from the package's length, width and height. The calculator does this from the dimensions you enter, and smaller packaging can move a product to a cheaper fee.
Is this Amazon FBA calculator free?
Yes. It runs in your browser, needs no account and has no daily limit. Nothing you type is sent to a server.