How do I work out my real profit per Amazon sale?

The profit formula

Profit per sale is one subtraction. Start with what the customer paid and take away every cost that sale caused.

Profit per sale = price - product cost - referral fee - fulfillment fee - storage fee - shipping to Amazon - ad cost - returns allowance

Profit margin is that profit divided by the price, shown as a percent. If you keep $7.17 on a $30 sale, your margin is 23.9 percent. Always work in per-unit numbers first. Totals hide the one product that loses money.

What each cost means

• Product cost (cost of goods): what you paid for the unit, including freight to your warehouse and duties.
• Referral fee: Amazon's cut of each sale. It is a percent of the total price, or a minimum amount, whichever is greater. As of November 2026, Amazon lists 15% for Home and Kitchen, Sports and Outdoors, and Toys and Games, with a $0.30 minimum. Beauty, Health and Personal Care and Baby Products are 8% on items of $10 or less and 15% above that. Check your own category on Amazon's pricing page.
• Selling plan: $39.99 a month for a Professional account, or $0.99 per item sold on the Individual plan, as of November 2026. Divide the monthly fee across your units.
• Fulfillment fee (FBA): what Amazon charges to pick, pack and ship an order when you use Fulfillment by Amazon, its warehouse and shipping service. It depends on the size and weight of the product.
• Storage fee: a monthly charge for the space your stock takes in Amazon's warehouses.
• Shipping to Amazon: what it costs you to send stock in.
• Ad cost: your Amazon Ads spend for that product, spread over the units it sold.
• Returns allowance: the average cost of returns, spread over every unit you sell.

A worked example

These figures are made up to show the method. Your fulfillment and storage fees will differ, so look them up for your own product.

Line	Per unit
Selling price (Home and Kitchen)	$30.00
Product cost	-$9.00
Referral fee, 15%	-$4.50
FBA fulfillment fee (example figure)	-$5.00
Storage fee (example figure)	-$0.30
Shipping to Amazon (example figure)	-$0.50
Ad cost per unit sold (example figure)	-$3.00
Profit before returns	$7.70 (25.7%)
Returns allowance (see below)	-$0.53
Profit after returns	$7.17 (23.9%)

Now the returns line. Say 6 of every 100 units come back. When you refund a customer, Amazon gives back the referral fee minus a refund administration fee, which its fee schedule sets at the lower of $5.00 or 20% of the referral fee (as of November 2026). A seller-software company, sellerboard, says the fulfillment fee is not refunded. Here that fee is 20% of $4.50, which is $0.90. So a return you can resell costs $0.90 plus the $5.00 fulfillment fee, or $5.90. Say 4 of the 6 are resellable and 2 are damaged, so you also lose the $9.00 product cost on those two.

Cost per 100 sales: 6 x $5.90 = $35.40, plus 2 x $9.00 = $18.00. Total $53.40, or $0.53 a unit. That is the line in the table.

Amazon's free calculator

The Revenue Calculator lets you search the Amazon catalog for a product, or enter its size, weight, category and price. It then estimates fees, costs and revenue, and it lets you compare Amazon fulfillment with shipping orders yourself.

It is the right first check before you buy stock. It is a single-product estimate, though. It does not know your ad spend, your real return rate, your freight or how many units sit in storage for months. Treat it as the top half of the table above.

Where calculators go wrong

• Ads left out. Ad spend is often the biggest cost after the product itself. A product that makes $10.70 before ads and spends $4 on ads is a $6.70 product.
• Returns left out. Returns look small per unit and large per year.
• Old product costs. If your supplier raised the price in the spring and your sheet still has the old one, every profit number is too high.
• Estimates versus actuals. A calculator predicts. Your payout report records what really happened. The gap between the two is where surprises live.
• Looking at Amazon alone. If you also sell on your own Shopify store, an online store platform, one channel can look great because the other is carrying shared costs.

How to calculate for every product, step by step

1. Export your product list with SKUs (your own product codes).
2. Add the true landed cost for each SKU: product, freight and duties.
3. Pull actual fees per SKU from your Amazon payout data, not the estimate.
4. Add ad spend per SKU from your ads report.
5. Add the returns allowance per SKU from your real return rate.
6. Compute profit per unit and margin for each SKU, then sort from worst to best.

Sorting is the point. The bottom of that list is your first decision: raise the price, cut the ads, or stop reordering.

Seeing every channel at once

A spreadsheet can do this for a handful of products. Once you sell across Amazon, Shopify and other marketplaces, the copy-and-paste work grows every month. A KPI dashboard pulls the same numbers from each channel into one screen automatically, so profit per product is already calculated when you open it. If you sell on Amazon and Shopify and your numbers live in several places, the Shopify reporting limits article shows what AI can and cannot fix there.

For inventory problems that quietly eat profit, see Amazon FBA inventory problems.

How I'd approach this

I would start with the table above in a spreadsheet and fill it in for your five best-selling products. Use real payout data for the fees and your supplier invoices for the costs. Do not use list prices or guesses.

When that works, do the same for every product and look at the bottom of the list. In my experience the surprise is rarely the top seller. It is the long tail, where a few products lose money after ads and returns.

If you are tired of rebuilding the sheet each month, that is the sign to automate it. I build profit dashboards that pull from Amazon and Shopify together, so you open one page and see profit per product. The point is that you see the real number without doing the work.