Amazon will happily show you sales. It will never show you, in one place, what you actually keep after every fee it charged. That number is the only one that matters, and you have to build it yourself.
Open Seller Central and you see sales, units, maybe a fees summary. What you do not see is true profit per unit after every cost is subtracted, because those costs are scattered across the settlement report, separate advertising invoices, your inventory records, and your own overhead. The blended "profit" most sellers carry in their head is gross sales minus whatever fees they happened to notice. The term "accounting for amazon" pulls roughly 2,400 searches a month, and the volume exists because almost nobody can answer "what is my real margin on this SKU" without rebuilding it from scratch.
True profitability is built bottom-up, one cost layer at a time. Skip a layer and you overstate profit. Here is the full stack.
Start with revenue and subtract everything, in order.
| LAYER | COST | NOTES |
| Revenue | Gross sales | Per SKU, at the point of sale |
| − COGS | Landed product cost | Per-unit FIFO: product + inbound freight + duties |
| − Referral fee | Amazon's commission | A percentage of sale price, by category |
| − FBA fee | Fulfillment per unit | Pick, pack, weight handling (FBA only) |
| − Storage | Monthly + long-term FBA storage | Allocated per unit held |
| − Advertising | Attributed PPC | Sponsored Products mapped to the SKU |
| − Returns | Refunds + return processing | Net of any reimbursement |
| \= True profit | What you actually keep | Per unit, per SKU |
Each layer is a real, nameable cost. The ones sellers most often forget are storage (especially long-term), attributed advertising, and the true cost of returns net of reimbursement. Those three are usually the difference between the profit you think you have and the profit you have.
Take a SKU selling at $40 with a landed cost of $14.
True profit per unit: $40 − $14 − $6 − $5 − $0.50 − $5 − $1.50 = $8, a 20% net margin.
The fee figures here are illustrative. Amazon's referral percentages vary by category and its FBA fees change periodically, so check your current rates rather than trusting any fixed table. The point is the shape: a 65% gross-margin product lands at 20% net, and if advertising or returns run hotter than assumed, that 20% can vanish. A seller watching only the 65% would scale this SKU aggressively and be baffled when cash got tight.
Blended margins average your winners and losers into a number that hides both. A business-wide 18% net margin can be made of one product at 35% subsidizing three products at break-even and one quietly bleeding. You cannot fix what you cannot see. Per-SKU true profit tells you which products to scale, which to reprice, which to renegotiate with the supplier, and which to kill.
This is also where fulfillment choices get decided properly. An FBM version of a SKU carries no FBA fee but real shipping and handling you pay directly. Only a true per-unit calculation that includes those direct costs lets you compare FBA and FBM honestly.
The cost stack is conceptually simple and operationally brutal to maintain by hand across thousands of SKUs and several channels, with fees that change and COGS that shifts batch to batch. This is the calculation ConnectBooks runs: it syncs Amazon, Shopify, Walmart, eBay, and TikTok Shop settlement data into QuickBooks or Xero, applies FIFO COGS per unit, and assembles per-channel P&L so true profit is computed continuously rather than reconstructed quarterly. For forward-looking analysis, which SKUs to fund, where cash lands in 90 days, Crunch, the AI CFO, is in active beta with a waitlist for the full release. See /crunch and /integrations/amazon-accounting.
| NEXT STEPKnow your true profit on every SKU, after every fee. ConnectBooks builds per-unit, per-channel profitability automatically, starting at $149/mo. See /pricing. |
Start with the sale price and subtract every cost in order: per-unit FIFO COGS, the referral fee, the FBA fulfillment fee, allocated storage, attributed advertising, and returns net of reimbursement. What remains is true profit. The costs sellers most often miss are storage, attributed PPC, and the real cost of returns.
Because Seller Central does not subtract every cost in one place. Advertising may be on a separate invoice, storage is easy to overlook, returns net of reimbursement are rarely allocated, and COGS lives in your own records. The dashboard shows sales and some fees, not true bottom-line profit per unit.
Long-term storage fees, attributed advertising spend at the SKU level, and the true cost of returns after netting any Amazon reimbursement. These three are routinely left out, and together they are usually the gap between the profit a seller assumes and the profit they actually earn.
Per SKU. A business-wide margin averages winners and losers into one number that hides both, so you cannot tell which products to scale and which are draining cash. Per-SKU true profit shows exactly where to invest, reprice, renegotiate, or discontinue.
Yes. Referral percentages vary by category and FBA fees are updated periodically, so any fixed fee table goes stale. Pull current rates from Amazon or use a tool that syncs the actual fees charged on your settlement report, which keeps your per-unit profit based on what you were really charged rather than an estimate.
Clean, accurate books make this manageable. Start a free trial of ConnectBooks to get settlement-level accuracy and real margin visibility for your ecommerce business. No credit card required.
Running an e-commerce business comes with plenty of challenges, but ConnectBooks is here to make your life easier. With real-time insights, seamless integrations, and detailed tracking of your profitability and inventory, you can stay ahead of the game. Whether you’re selling on Amazon, Shopify, Walmart, TikTok or eBay, ConnectBooks helps you manage your finances with 100% accuracy and confidence, so you can focus on growing your business.
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