What do you actually earn on an Amazon product?
After the first month, every new seller says the same sentence: "I sold this much — so where is the money?"
The answer is almost always the same. The Seller Central homepage shows revenue. That number is not yours. By the time the money reaches your bank account, five or six different items have come out of it, and most of them never appear on a single screen together.
Let's walk through what actually comes out, and how to see, per product, whether an item earns you money or just moves.
What comes out of a sale
1. The referral fee. A category-dependent percentage of the sale price. Look up the exact figure for your own category in the Seller Central fee schedule: it differs by category, and Amazon changes it from time to time. It is always deducted, even when you ship the order yourself.
2. The FBA fulfillment fee. When the parcel ships from Amazon's warehouse, this depends on the size and weight of the box, not its price. That is why, out of two similarly priced products, one can earn and the other cannot: one of them crossed a size threshold by two centimeters.
3. Storage fees. A monthly charge on inventory sitting in the warehouse, much higher in the fourth quarter. If the stock does not move, this line keeps eating.
4. Refunds and returns. A returned product is not a neutral event: the buyer gets the price back, part of the referral fee is kept, and the product often cannot be sold again.
5. Advertising cost. The sneakiest one, because it does not arrive per product line. If your campaign covers several items, the aggregate ads number in Seller Central will not tell you which product paid for itself.
6. Your cost of goods. Amazon does not even know this one. It is the only item that only you can add to the formula — and it is exactly the one that decides profitability.
The formula worth writing down
Net margin = sale price
- referral fee
- FBA fee
- prorated storage fee
- refund-rate impact
- advertising cost (for that product)
- cost of goods and inbound shippingThis number can be negative even on a product that sells nicely. In fact, a well-selling product can produce the biggest loss, because it multiplies the mistake by the unit count.
The three mistakes beginners repeat
Watching revenue instead of profit. A rising revenue chart feels good, but it is not information. Twenty percent more revenue on a worsening margin is less money.
Treating advertising as a separate budget. PPC is not a marketing budget somewhere at the edge of your books — it is the cost of selling that specific product. If you do not account for it where it is incurred, every product-level margin number you have is wrong.
Watching the average instead of the product. The average margin across your portfolio tells you roughly nothing. The typical situation is that two or three items carry the profit while the rest float at or below zero. You only see that when you break it down to SKU level.
How SellHelm helps here
You can do this arithmetic by hand. Many sellers do: they export the order report, put the fee report next to it, add the cost of goods manually, and take a run at it once a month. There are two problems: it takes hours, and by the time it is done, it describes the past.
SellHelm's profit module keeps the same calculation continuously up to date. You connect your Amazon account, it pulls in the orders and the fees that belong to them, and you add the one thing only you know: your cost of goods and your own expenses. The result is net margin, not revenue, per product — and not once a month, but continuously.
Your inventory and your advertising data live on the same surface. That matters because the three questions are connected: is this product worth it, do I have enough of it, and how much am I spending on it. If those live in three different tabs, the answer will always be mental arithmetic.
SellHelm's seller tools are free with every account, and profit calculation is one of them. Keyword-level campaign management (Campaign Manager, 99 USD/mo) is a separate line, and it is coming soon.
Where to start if you are starting now
1. Pick your three best-selling products. 2. Write the formula above down for each of them, per unit. A spreadsheet is enough. 3. Check which one stays positive once you add the advertising cost. 4. If one is negative: do not switch off the ads first. Look at the size threshold, the cost of goods and the return rate — those are the bigger and more durable items.
Once you have the three numbers, you have something to work on. That is the point: you do not become profitable by selling more, but by knowing which product earns.
Related: When should you reorder?