Amazon FBA profit margin is what's left of the sale price after Amazon's referral fee, the FBA fulfillment fee, storage and inbound charges, your landed cost, a returns reserve, and ad spend, divided by the price. Net per unit is the same subtraction before you divide. Every line already sits on a report in your seller account. This page names each fee, says where it lives, and works the math on one product from the sample catalog with every assumption labeled.
The formula
Landed cost is the supplier's price plus freight and duty to reach you. Inbound per unit is what it then costs to reach Amazon's warehouse, including the inbound placement fee. Ad cost per unit is the month's ad spend on the SKU divided by every unit it sold, not just the ad-attributed ones.
Margin is a share of the price, and so is every percentage fee Amazon charges, so raising the price never raises the margin one for one. The margin calculator does everything up to ads; the template takes ads off the end.
Every fee between the sale and your payout
Amazon's public pricing pages (2026) name the fees below. How each is charged matters more than this year's rate: a percentage fee scales with your price, a per-unit fee doesn't, and a monthly fee has to be spread over what you actually sold.
| Fee | How it's charged | Where you find yours | Calculator field |
|---|---|---|---|
| Referral fee | Percentage of the total price, or a per-item minimum, whichever is greater. 5% to 45% by category on Amazon's 2026 schedule. | Amazon's selling fees page; Fee Preview report | Marketplace fee, % of price |
| FBA fulfillment fee | Per unit, by size, weight and price. | Fee Preview report; Revenue Calculator | Shipping you pay per unit |
| Monthly storage | Per cubic foot of daily average volume, plus an aged-inventory surcharge past 181 days. | Payments dashboard | Packaging per unit, as storage per unit |
| Inbound placement fee | Per inbound shipment, for spreading inventory across fulfillment centers. | Shipment fee summary; Payments | Inbound freight per unit |
| Shipping to Amazon | Per shipment, to the fulfillment center. | Your carrier's invoice | Inbound freight per unit |
| Prep and labeling | Per unit, yours or Amazon's. | Supplies invoice; Payments | Packaging per unit |
| Returns processing, refunds, write-offs | The processing fee lands on orders with free customer return shipping; refunds and unsellable units are the rest. | Payments and the returns report, last 90 days | Returns reserve, % of price |
| Advertising | Per click on Sponsored Products; you set bids and a daily budget. | Advertising console, spend by SKU | Not in the calculator; the template's ad_cost_per_unit column |
Two lines sit outside the per-unit math. Amazon's pricing page (2026) lists the Individual plan at $0.99 per item sold and the Professional plan at $39.99 a month; the first is a per-unit cost, the second is overhead your net has to cover. And there's no separate card-processing line in Amazon's schedule, so the sample catalog sets Card processing to 0 on its Amazon rows.
Where to find each fee for your product
Amazon's own FBA fees guide (July 2026) points at three places. The Fee Preview report (Seller Central: Reports, Fulfillment, Payments, Fee preview) is the per-SKU fee estimate for what you already carry. The Revenue Calculator, public at sellercentral.amazon.com/revcalpublic, takes a product's dimensions, weight, category, price and shipping charge and shows Amazon fulfillment beside your own; it's for a product you haven't listed yet, and it's an estimate, not a bill. The Payments dashboard is what Amazon actually charged, where storage, inbound and refund lines live. Ad spend is in the advertising console; supplier price and freight are on your own invoices.
Turning a monthly bill into a per-unit cost
Divide by everything the SKU sold, organic and advertised alike: storage held every unit and the ads lifted the whole listing. For the returns reserve, divide 90 days of refunds, processing fees and write-offs by 90 days of gross sales.
A worked example, with every assumption labeled
The margin calculator's sample catalog, a small store called Northside Goods, sells two products on Amazon. Take the enamel camp mug. Every number is the sample's or an assumption marked as one; replace each with yours.
- Sell price
- $18.00
- Landed cost
- $4.20 unit cost + $0.70 inbound freight = $4.90 (in yours, shipping to Amazon and inbound placement per unit go in that $0.70)
- Referral fee
- 15% × $18 = $2.70 (assumption: the sample's rate; use your category's)
- FBA fulfillment fee
- $3.90 (assumption: the sample's stand-in; yours is on the Fee Preview report)
- Prep and packaging
- $0.50 (poly bag and label)
- Storage per unit
- $9.60 for the month ÷ 48 sold = $0.20 (assumption)
- Returns reserve
- 4% × $18 = $0.72
- Net per unit before ads
- $18 − $4.90 − $2.70 − $3.90 − $0.50 − $0.20 − $0.72 = $5.08
- Margin before ads
- $5.08 ÷ $18 = 28.2%
In the calculator, the sample's mug row reads $5.28 and 29.3% because it carries no storage line. Add the $0.20 to Packaging per unit and it lands on $5.08.
- Sponsored Products spend on the SKU
- $86.40 for the month (assumption)
- Units sold, organic and advertised
- 48
- Ad cost per unit
- $86.40 ÷ 48 = $1.80
- Net per unit after ads
- $5.08 − $1.80 = $3.28
- Margin after ads
- $3.28 ÷ $18 = 18.2%
- Ad ceiling
- $5.08 per unit sold; more than that on ads and the mug loses money
Ten points of margin went to ads. That's the number the Revenue Calculator won't show you, and the one that decides whether the listing is worth running.
The same mug on Amazon and on your own store
Put the mug on the store's own site at the same price with the catalog's own-store assumptions: card processing at 2.9%, the $4.50 small-parcel shipping the store absorbs, a 3% returns reserve, no marketplace fee. If your store runs on Shopify or a similar platform, its processing rate is the Card processing field and its monthly plan is overhead.
| Per unit | Amazon FBA | Your own store |
|---|---|---|
| Sell price | $18.00 | $18.00 |
| Landed cost | $4.90 | $4.90 |
| Referral or marketplace fee | $2.70 (15%) | $0 |
| Card processing | $0 (no separate line) | $0.52 (2.9%) |
| Fulfillment or outbound shipping | $3.90 | $4.50 |
| Prep and packaging | $0.50 | $0.50 |
| Storage per unit | $0.20 | $0 (your shelf) |
| Returns reserve | $0.72 (4%) | $0.54 (3%) |
| Net before ads | $5.08 (28.2%) | $7.04 (39.1%) |
| Ad cost per unit (assumption) | $1.80 | $3.50 |
| Net after ads | $3.28 (18.2%) | $3.54 (19.7%) |
The referral and fulfillment fees are the swing, about $2 a unit before ads in the store's favor. What Amazon gives back is the traffic. On your own store every click is yours to buy, so the honest comparison is the last two rows, and the own-store ad number is the assumption to test hardest.
What a good margin means for your product
No single number answers this, and the people who publish one disagree. Amazon's own seller blog (July 2026) says many ecommerce businesses aim for a net margin of 10% to 20%, then prints a table where electronics run 5% to 10% net and beauty 15% to 25%. A benchmark says what other categories carry. Whether your mug pays its way comes from your fixed costs.
Fixed costs are the Professional plan, software, your time, and anything else that doesn't change with volume, split across products however you like.
- Fixed costs assigned to the mug
- $96 a month (assumption)
- Expected units
- 48 a month
- Required net per unit
- $96 ÷ 48 = $2.00
- Actual net after ads
- $3.28
- Room
- $1.28 a unit; ad spend could rise to $3.08 per unit before the mug stops covering its share
A good margin clears your required net with room for the fees to move. Below it, the percentage is the wrong question; the price, the ad budget, or the fulfillment method is the answer.
Fees change. Recalculate.
Today's estimate holds until something moves, and something always moves: the fee schedule gets revised, a packaging change shifts the size tier, a slow month leaves units past 181 days in storage, ad costs drift. Recalculate when a fee notice arrives, when you change price or packaging, and once a quarter from actual Payments numbers rather than the Fee Preview estimate.
How to do yours
- Pull your product's referral fee percentage and FBA fulfillment fee from the Fee Preview report (Reports, Fulfillment, Payments, Fee preview). For a product you don't list yet, enter its dimensions, weight, category and price in the Revenue Calculator.
- From last month's Payments dashboard, total the storage, inbound placement, prep and returns charges on the SKU and divide each by the units it sold. Take the supplier's price and the freight to you and to Amazon from your own invoices.
- From the advertising console, divide the month's spend on the SKU by every unit it sold, advertised or not, for ad cost per unit.
- Enter the row: sell price, unit cost, inbound freight per unit (freight to you plus shipping to Amazon and inbound placement), duties, packaging per unit (prep plus storage per unit), card processing at 0, marketplace fee at the referral percentage, shipping you pay at the fulfillment fee, and the returns reserve. Read net per unit and margin.
- Subtract ad cost per unit from net per unit yourself, then compare it with the required net per unit from your fixed costs. That comparison, not a benchmark, says whether the margin is good.
- Add a second row for the same product on your own store with your processor's rate, your shipping and no marketplace fee. The CSV template below has every column with the formulas filled in, or start in the margin calculator and enter the rows there.
Questions people ask
How do you calculate Amazon FBA profit margin?
From the sale price, subtract the referral fee, the FBA fulfillment fee, storage per unit, inbound per unit, landed cost, a returns reserve, and ad cost per unit. That's net per unit; divide by the price and multiply by 100 for the margin. The sample mug nets $3.28 on $18, an 18.2% margin after ads.
What is a good profit margin for Amazon FBA?
One that clears the net per unit your fixed costs require, with room for fees to move. Benchmarks disagree by category, and Amazon's own 2026 guidance spans 10% to 20% net, so compute your required net (monthly fixed costs divided by expected units) and judge against that.
What fees does Amazon charge FBA sellers?
A referral fee as a percentage of the price with a per-item minimum, a per-unit fulfillment fee by size and weight, monthly storage by cubic foot with an aged-inventory surcharge past 181 days, an inbound placement fee, a returns processing fee on orders with free customer returns, removal and disposal fees, and the selling plan. Advertising is separate, priced per click.
Should advertising be included in FBA profit margin?
Yes, per unit: the month's ad spend on the SKU divided by every unit it sold, advertised or organic, because the ads lift the whole listing. The margin calculator stops before ads, so subtract this from its net per unit yourself; the template has the column.
Is it cheaper to sell on Amazon or on your own store?
Per unit before ads, your own store skips the referral fee and pays your processor's rate instead of a category percentage, so it comes out ahead on paper. After ads it depends on what a sale costs to bring in. Run both rows and compare net after ads, not the fee lines.