Amazon FBA Profitability Calculator

How Amazon FBA fees work

When you sell through Amazon FBA (Fulfillment by Amazon), Amazon stores, packs and ships your product. In return they charge several fees that come straight off your profit. This calculator takes each one as an input rather than guessing, so plug in the exact numbers from your Amazon Seller Central account and you get your figures rather than somebody’s averages.

Referral fee

A percentage of the sale price, usually about 15% for most categories. Some categories are lower, a few higher, and there is a minimum of $0.30 per item that only ever bites on very cheap products. Enter your category’s rate.

FBA fulfillment fee

Charged per unit shipped, based on the product’s size tier and weight. Rough values:

• Small Standard (16 oz or under): about $3.22 a unit
• Large Standard (up to 3 lb): about $5.42 a unit
• Small Oversize (up to 70 lb): about $9.73 a unit

Look up your product’s exact fee in Seller Central and enter that. The size tier matters more than the weight does, and a package that crosses a tier boundary by a quarter inch costs a dollar more forever.

Monthly storage fee

Amazon charges for space in the fulfillment center, roughly $0.87 per cubic foot from January to September and about $2.40 per cubic foot from October to December. For a small standard item that is a few cents per unit per month. Enter your per-unit monthly figure and the calculator multiplies it by how long the average unit sits there.

That October jump is why so many FBA sellers who did the math in spring get a nasty fourth-quarter statement. Nearly triple the rate, on inventory that has usually also been built up for the holidays.

Profit formula

Referral fee = sale price × referral %
Storage fee per unit = monthly storage fee × storage months
Profit per unit = sale price − referral fee − FBA fee − storage fee − COGS (Cost of Goods Sold)

Worked example

A $24.99 product, $6 of goods including the shipment into Amazon, 15% referral, $3.22 fulfillment, $0.05 a month of storage, two months on the shelf:

• Referral: $24.99 × 0.15 = $3.75
• FBA fulfillment: $3.22
• Storage: $0.05 × 2 = $0.10
• Amazon takes $7.07 in total, 28.3% of the sale price
• Profit: $24.99 − $7.07 − $6.00 = $11.92 a unit, a 47.7% margin

At 50 units a month that is $596.07 of profit, or $7,152.90 a year, from one product.

Tips for FBA sellers

Aim for at least 25 to 30% net margin after every fee. Storage costs multiply fast, so slow-moving inventory is worse than it looks on a spreadsheet. And always fold the cost of shipping your goods into Amazon into the cost of goods, because it is the line new sellers most often forget and it is rarely small.