How do you calculate profit margin on Amazon?

The profit margin formula

There are two margins worth tracking. Gross margin shows how profitable the product is before marketplace costs; net margin shows what you actually keep after Amazon takes its cut and you spend on ads. Net margin is the number that tells you whether the business works.

Calculate gross margin first, then layer in Amazon's fees and advertising to reach net margin.

One definitional point that saves arguments later: revenue means the price the buyer paid for the product (plus any shipping you charged), not the deposit Amazon sent you. Amazon's payout arrives with fees already removed, so dividing by the payout instead of true revenue inflates your margin percentage and hides how much Amazon is actually taking. Always build the calculation from gross sales down, never from the bank deposit up.

It's also worth separating margin from ROI, because sellers use them interchangeably and they answer different questions. Margin divides profit by revenue and tells you how efficiently a sale converts to profit. ROI divides profit by your cash invested (the landed cost) and tells you how hard your capital is working. A $10 item that nets $3 has a 30% margin and, if it cost you $4 landed, a 75% ROI. High-ROI, low-margin products can be excellent if they turn fast; the two numbers together tell the real story.

One more distinction is worth keeping straight, because it decides whether a product deserves your cash at all. What you're computing here is accounting profit: revenue minus the explicit costs you actually paid. Economic profit goes a step further and subtracts opportunity cost, meaning the return that same money and time could have earned elsewhere. A store netting 8% while the owner turns down a salaried job and keeps six figures tied up in stock can show healthy accounting profit and negative economic profit at once. Accounting vs economic profit isn't a classroom distinction for a seller deciding whether to reorder. Everything below is also pre-tax; income taxes for Amazon sellers come out of net profit afterward.

• •Gross profit = Revenue - COGS
• •Gross margin = (Revenue - COGS) / Revenue x 100
• •Net profit = Revenue - COGS - Amazon fees - FBA fees - storage - ads - returns
• •Net margin = Net profit / Revenue x 100

A worked example

Take one unit selling for $30. These numbers are illustrative, and the Amazon fee figures below are placeholders, not current rates, because referral and FBA fees vary by category, size, and weight and change over time, so always verify them against Amazon's current fee schedule.

Sale price $30. Subtract landed product cost (COGS) of $9, an illustrative referral fee of $4.50, an illustrative FBA fulfillment fee of $5, and $3 of advertising allocated to that unit. Net profit = $30 - $9 - $4.50 - $5 - $3 = $8.50. Net margin = $8.50 / $30 = 28.3%. Notice gross margin looked healthy at ($30 - $9) / $30 = 70%, but Amazon's fees and ads cut the real margin to under 30%. That gap is why net margin is the number that matters.

Now stress-test it, because static examples flatter you. Suppose your ad spend rises by $1.50 per unit during a competitive quarter. Net profit drops to $7.00 and margin to 23.3%. Add a return rate where, say, one unit in twenty comes back and can't be resold: that's roughly another $1.05 of cost spread across each sold unit, pulling margin near 20%. Nothing dramatic happened. No single fee changed. Two ordinary pressures stacked, and a third of the margin evaporated. This is why per-unit margin needs to be recalculated whenever an input moves, not set once at product launch.

• •Revenue: $30.00
• •Less COGS: $9.00 (gross margin 70%)
• •Less referral fee: $4.50 (illustrative)
• •Less FBA fulfillment: $5.00 (illustrative)
• •Less advertising: $3.00
• •= Net profit $8.50 -> net margin 28.3%

Where each number actually comes from

The formula is easy; sourcing honest inputs is the work. Revenue and every fee Amazon charged live in your settlement reports (Payments > All Statements in Seller Central). Settlements itemize each order's principal, referral fee, FBA fee, and any adjustments, which makes them the ground truth for what Amazon took. The fee preview columns in inventory reports are estimates; settlements are what actually happened.

COGS should be your landed cost per unit: supplier price plus inbound freight, duties, and whatever a prep center for Amazon FBA charges to label and pack the units, divided across the shipment. Sellers who use the bare supplier invoice understate COGS and overstate margin, sometimes by several points. If you haven't computed landed cost, do that first; every margin number downstream depends on it.

Advertising comes from the Ads console, and the honest move is allocating it per SKU, not spreading account-wide spend evenly. A product with heavy launch spend can run at a planned loss while the rest of the catalog subsidizes it. That's a fine strategy, but only when you can see it happening. Storage fees, long-term storage surcharges, and inbound placement fees appear in settlement adjustments and monthly charges; allocate them to SKUs by the space and time each product actually consumed, even roughly. Rough allocation beats ignoring them.

Don't forget the hidden costs

The example above is still optimistic because it leaves out costs that quietly eat margin: long-term storage fees, returns and refunds, removal and disposal fees, inbound placement fees, and the carrying cost of unsold stock. Across a full catalog these can move a 28% line-item margin down to a low double-digit business margin.

Returns deserve special attention because they hit margin twice. You refund the revenue, and you often lose part of the fee or the unit itself when it comes back unsellable. A category with a high return rate needs several extra points of headline margin just to net the same as a low-return category. Compare products on post-return margin, not listing-price margin.

If the same catalog sells elsewhere, run the fee math per channel instead of assuming Amazon's structure carries over. To calculate eBay listing fees, start with the insertion fee on listings beyond your monthly free allotment, add the final value fee, which is charged on the total the buyer pays including shipping and tax, then add any Promoted Listings rate you opted into. Those are the eBay hidden fees people complain about, and they aren't really hidden: they're just charged on a bigger base than sellers expect. Same formula, different inputs.

Because so many of those costs are Amazon fees that shift over time, model them per unit before you launch a product. A free FBA profit calculator lets you plug in your landed cost and current fees to see net margin per unit, and a free FBA reimbursement audit recovers margin you've already lost to units Amazon lost or damaged but never credited back.

Reading your margin against a real retailer

A 28% net margin sounds unremarkable until you set it next to the businesses moving the same kinds of products at scale. Walmart profit margins are the handy reference because anyone can look them up. Walmart gross margin runs far below what a private-label seller sees on a unit, since a retailer buys finished goods and marks them up modestly rather than sourcing at manufacturing cost, and the Walmart net profit margin after operating costs lands in low single digits. Pull the current Walmart gross profit margin and net figure from their annual report rather than from any article, including this one, because they move year to year.

The point isn't that you're outperforming Walmart. It's that a margin percentage means very little without volume and turn attached to it. Walmart's thin margin earns billions because inventory turns constantly and the same capital recycles many times a year. A seller holding a 40% margin on a SKU that moves six units a month has a hobby. Margin, turn rate, and capital employed are one question, not three, which is why the ROI comparison earlier in this page matters as much as the margin itself.

Common margin calculation mistakes

Mistake one: treating the Amazon deposit as revenue. Covered above, but it's the single most common error and it makes every downstream percentage wrong, so it bears repeating once.

Mistake two: computing margin from estimated fees forever. Estimates are fine for launch decisions. Months later, the actual fees on your settlements have drifted (a size-tier reclassification, a fee schedule update, a storage surcharge), and sellers still quoting their launch spreadsheet are quoting fiction.

Mistake three: ignoring your own labor and overhead. Per-unit margin excludes software subscriptions, prep supplies, your bookkeeper, and your time. That's correct for SKU-level decisions, but the business's real profitability needs those loaded in. A catalog of 25% margin SKUs can still be an unprofitable company.

Mistake four: averaging everything. A blended 18% account margin might be one hero SKU at 35% carrying five products at breakeven and two losing money outright. Averages are where bad SKUs hide.

Mistake five: measuring margin on sold units only and forgetting the stock that never sells. If you buy 1,000 units and end up disposing of 80 after long-term storage fees pile up, the cost of those 80 belongs to the product's economics. A per-unit margin that ignores sell-through looks better than the product ever performed. When you review a product's lifetime profitability, divide total profit by total units purchased, not units sold; the difference is the honest cost of overordering.

Calculate margin at the SKU level, every month

A blended account-wide margin hides which products make money and which bleed. The unit above looks fine, but the same catalog often contains SKUs at negative net margin once you load in returns and storage. You only see this by calculating margin per SKU, and by refreshing it monthly as fees and ad spend move.

Any accounting software will hand you a profit and loss statement for the account as a whole, and that's a genuinely useful document for tax and for tracking overhead. It just can't answer the question in this section, because a P&L totals the business while margin work happens one SKU at a time.

Doing that by hand means parsing every settlement file and mapping thousands of fee lines back to SKUs, which is exactly the kind of work amazon accounting software exists to automate. A good tool ingests each settlement, splits it into sales, fee types, refunds, and adjustments, and posts summarized entries to your ledger; if you keep books in QuickBooks, an amazon quickbooks integration should make each deposit match a balanced journal entry to the penny. When comparing amazon seller accounting software, the differentiator for margin work is whether it ties real landed cost to real settlement fees per SKU, not just whether it categorizes transactions. Plenty of tools do clean amazon bookkeeping at the account level but can't tell you which product is bleeding.

BeanHawk computes per-SKU profitability using your real landed cost and the actual fees Amazon charged on each settlement, so margin is based on what happened, not on estimates. A2X and Link My Books are worth evaluating alongside it if settlement-to-ledger sync is your main need. Whichever amazon fba accounting setup you choose, the test is simple: can you name your three worst-margin SKUs right now, with numbers? If not, the tooling isn't doing its job.

Check any product's margin instantly with the FBA profit calculator: enter price and costs to see margin and ROI after fees.