How to Calculate Amazon FBA Profit Before Buying

Six steps and one formula. The exact maths Profit Scanner runs on every product in your supplier list.

Updated May 2026 · Reflects Amazon’s 20 March 2026 Digital Services Fee policy.

Short answer: Amazon FBA profit on a wholesale unit is net_sale − net_buy − gross_fees − dsf_fee − prep_cost. The trick is computing each piece correctly: extract VAT from the sale price, decide whether your supplier invoice is gross or net, apply the live Amazon rate card, deduct the new Digital Services Fee, and subtract your per-unit prep cost. Below is the full breakdown.

  1. 1

    Compute the net sale price

    Amazon prices include VAT. Divide the listing price by (1 + VAT/100) to extract the net amount you actually keep before any fees.

    net_sale = amazon_price / (1 + vat_sale_rate / 100)

    Example: Listing €30 on Amazon.it (22% VAT): net_sale = 30 / 1.22 = €24.59

  2. 2

    Compute the real buy cost

    Three cases depending on your VAT registration. If your supplier price has VAT and you can reclaim it, divide by (1 + VAT/100). If you are not VAT-registered and the supplier gave you a NET price, add VAT back. Otherwise use the gross supplier price.

    net_buy = buy_price / (1 + vat_buy / 100)   if VAT-registered
or buy_price * (1 + vat_buy / 100)   if not VAT-registered + NET supplier price
or buy_price                              otherwise

    Example: EU VAT-registered seller, supplier invoice €12 incl. 22%: net_buy = 12 / 1.22 = €9.84

  3. 3

    Add Amazon fees

    Amazon charges referral (% of sale price, varies by category) plus FBA fulfilment (per-unit, depends on size and weight). Both come from the live rate card. If your tax setup makes those fees VAT-bearing for you, multiply by (1 + standard VAT/100).

    gross_fees = referral_fee + fba_fee
(or that × (1 + vat_sale / 100) if fee VAT applies)

    Example: Referral 15% on €30 = €4.50; FBA size-S small = €2.85. gross_fees = €7.35

  4. 4

    Subtract Digital Services Fee (DSF)

    Since 20 March 2026 Amazon applies a Digital Services Fee on top of referral and FBA in UK, FR, IT, ES (and other markets). Two rates apply separately to the two fee components, depending on your seller establishment country.

    dsf_fee = referral_fee × (dsf_rate_referral / 100) + fba_fee × (dsf_rate_fba / 100)

    Example: UK seller on Amazon.co.uk: 2% on referral + 2% on FBA. dsf_fee = (4.50 + 2.85) × 0.02 = €0.147

  5. 5

    Subtract prep cost

    Bags, labels, polybags, fragility tape — anything you pay your prep centre per unit. A flat number per unit is enough.

    prep_cost = whatever you pay your prep centre per unit

    Example: 3PL charges €0.40/unit. prep_cost = €0.40

  6. 6

    Compute profit, margin and ROI

    Profit is what you keep after every cost. Margin tells you how much of the net sale becomes profit. ROI tells you how much you earn for every euro you put in.

    profit = net_sale − net_buy − gross_fees − dsf_fee − prep_cost
margin% = profit / net_sale × 100
roi% = profit / (net_buy + prep_cost) × 100

    Example: profit = 24.59 − 9.84 − 7.35 − 0.15 − 0.40 = €6.85 margin = 6.85 / 24.59 = 27.9% roi = 6.85 / (9.84 + 0.40) = 66.9%

Frequently Asked Questions

Why divide the sale price by (1 + VAT/100)?

Amazon listing prices in EU/UK marketplaces include VAT. The platform pays out the net amount, not the gross. To compare apples to apples with your buy cost, you need to extract VAT first. For Italy that means dividing by 1.22 (22%); for Germany 1.19; for the UK 1.20.

When does the buy price already include VAT?

EU/UK suppliers usually invoice with VAT included unless you are a B2B customer with a valid VAT ID and they apply reverse charge. If your invoice shows a VAT amount you can reclaim, divide by (1 + VAT/100). If you are not VAT-registered and the supplier gave you a NET price, add VAT back. If unsure, ask your accountant once and apply the same rule across the catalogue.

Do reduced VAT rates change the formula?

Yes. Books, food, baby products and some health items have reduced VAT in EU markets (4–10% in IT/FR/ES/DE/UK). On the sale side, divide by 1 + reduced rate, not the standard one. On Amazon fees, the standard VAT rate applies — fees are services, services do not get the reduced rate. Profit Scanner detects category-level reduced VAT automatically and applies the correct rate per row.

What is the Digital Services Fee?

Amazon introduced a Digital Services Fee on 20 March 2026 across UK, France, Italy, Spain and Canada. The fee is applied on top of referral and FBA, with rates depending on the marketplace and the seller’s country of establishment. UK and France apply 2% to all sellers. Italy and Spain apply 3% on referral always, plus 3% on FBA only for sellers established in UK, IT, ES.

Is margin or ROI more important?

Both, for different decisions. Margin tells you how much each €1 of revenue contributes to profit — useful for pricing strategy. ROI tells you how much you earn relative to the cash you tied up — useful for cash-flow decisions. A 30% margin product with €15 profit per unit is great, but if it ties up €100 per unit your ROI is only 15%. A 15% margin product at €5 profit on €25 invested is 20% ROI — better cash velocity.

Why does Profit Scanner sometimes show different numbers from BuyBotPro / SellerAmp?

Three common reasons: (1) we apply reduced VAT per category automatically, others use a flat rate; (2) we deduct the Digital Services Fee — most calculators have not updated since the March 2026 change; (3) we use the live referral and FBA fee from the latest Amazon rate card, refreshed weekly. The differences are usually 1–4% on the margin number, larger on reduced-VAT categories.

Skip the spreadsheet

Upload your supplier list and Profit Scanner runs this formula on every row across 11 marketplaces, with live Amazon fees, reduced-VAT detection and 9 risk flags per product.