How FBA profit is calculated
Net revenue = Selling price (minus VAT if prices include VAT)
Storage = Monthly storage fee per unit × Months in storage
Amazon fees = Referral + Fulfillment + Storage + Other Amazon fees
Net profit per unit = Net revenue − Amazon fees − Product − Inbound − Prep − Advertising − Other
Margin = Net profit ÷ Net revenue · Return on product cost = Net profit ÷ Product cost
Monthly profit = Net profit per unit × Units sold per month
Break-even selling price
Let F be all costs that do not depend on price, r the referral rate and v the VAT rate included in the price (zero where prices exclude tax). Profit is zero when:
or, if the minimum referral fee m applies: P = (F + m) × (1 + v)
If the referral rate and VAT together absorb every extra unit of price, there is no break-even price and the calculator says so.
Where to find your fees
Use the fee preview and revenue calculator in Seller Central, or Amazon’s official fee schedule pages for your marketplace. Fees to look for include:
- Referral fee - a percentage of the sales price set by category, often with a per-item minimum.
- FBA fulfillment fee - a per-unit fee set by size tier and shipping weight.
- Monthly inventory storage - usually charged per cubic foot, and often higher in peak season.
- Other fees that may apply depending on marketplace and program, such as closing fees for some media categories, inbound placement or low-inventory fees, aged inventory surcharges and returns processing.
Divide any monthly or per-shipment fee by the number of units it covers to enter it per unit.
Worked example
Illustrative values only - these are not Amazon’s fees for any category or size tier.
| Selling price | $29.99 |
| Referral fee at 15% | −$4.50 |
| Fulfillment fee | −$5.20 |
| Storage $0.12 × 2 months | −$0.24 |
| Product, inbound shipping, prep | −$7.50 − $0.60 − $0.25 |
| Advertising per unit | −$2.40 |
| Net profit per unit | $9.30 (31.01% margin, 124% return on product cost) |
| Break-even price | $16.19 of fixed costs ÷ 0.85 = $19.05 |
| Monthly profit at 300 units | $2,790.00 |
The product could be discounted by about a third before it stops making money, but a price war below $19.05 would lose money on every unit.
How to use the results
- Net profit per unit is what each sale contributes after Amazon’s fees and your direct costs.
- Margin helps you compare products and channels; for a comparison with your own store, use theShopify profit margin calculator with the same product cost.
- Return on product cost tells you how productive your inventory spend is, which matters when cash is limited.
- Break-even price is your floor for promotions, coupons and repricing rules.
Common mistakes and limitations
- Using fees from the wrong marketplace or size tier. A small change in package dimensions can move a product into a more expensive tier.
- Forgetting VAT in UK and EU marketplaces, where listed prices include it and the referral fee is charged on the inclusive price.
- Using supplier price instead of landed cost. Add freight and duty with thelanded cost calculator.
- Ignoring storage time. Slow sellers pay storage for many months; set months in storage to your real average.
- Treating advertising as optional. If you need ads to sell, ad cost per unit is a real cost.
Methodology and sources
All amounts are per unit and calculated in whole cents, with each fee rounded once, half away from zero. The referral fee is the larger of the percentage fee and the minimum you enter. With VAT-inclusive prices, VAT is removed to find net revenue. Break-even price is solved algebraically, rounded up to the cent and checked against the fee rounding. No Amazon fee values are built into this calculator, so there is no fee schedule to go out of date; always confirm current fees in Seller Central for your marketplace.
Frequently asked questions
Does this calculator include Amazon’s current fees?
No. Amazon’s fees vary by marketplace, product category, size tier, weight, time of year and fulfillment program, and they change over time. To avoid showing out-of-date or invented numbers, every fee is entered by you from Seller Central or Amazon’s official fee pages.
How is the referral fee calculated?
As a percentage of the total sales price, with a minimum fee per item in many categories. This calculator charges the larger of the percentage and the minimum you enter. In marketplaces where prices include VAT, the percentage applies to the VAT-inclusive price.
What is the difference between margin and ROI?
Margin is net profit divided by net revenue: how much of each sale you keep. Return on product cost (ROI) is net profit divided by what you paid for the product: how hard your inventory money works. A product can have a modest margin but a high ROI if it is cheap to buy.
How is the break-even price worked out?
It is the lowest price, rounded up to the cent, at which net profit is zero or more. Because the referral fee and any included VAT grow with the price, each extra dollar of price only adds a fraction of a dollar of profit. The calculator solves for that point, including the minimum referral fee.
How should I enter advertising cost?
Divide your total ad spend for the product by all units sold, including organic sales, to get an average advertising cost per unit. Using cost per ad-attributed sale instead would overstate the cost of every unit.
What costs are not included?
Income tax, account-level subscription fees, refunds and return processing, removal or disposal fees and long-term storage surcharges are not included unless you enter them under other costs or other Amazon fees.