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Amazon FBA vs FBM Calculator

Real per-unit profit comparison for any SKU. Plug in price, weight, dimensions and expected velocity — see which fulfillment model actually wins. Math runs in your browser.

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RecommendationUse FBA

FBA wins by $2.75 per unit. At 60 units/mo, that's $164.75 more profit/month — and you don't pack the orders yourself.

FBA — Fulfilled by Amazon

Winner
Selling price
$24.99
Cost of goods
−$6.50
Referral fee
−$3.75
FBA fulfillment
−$4.20
Storage (avg/mo)
−$0.05
Profit/unit
$10.49

FBM — Fulfilled by Merchant

Selling price
$24.99
Cost of goods
−$6.50
Referral fee
−$3.75
Shipping label
−$5.50
Pack/handling
−$1.50
Profit/unit
$7.74

FBA fee data uses Alexandria's canonical 2026 model, built on Amazon's published rate schedule. FBM shipping uses USPS/UPS Ground national averages from May 2026 — actual cost depends on your label discount and zone. For live carrier-quoted rates and live SP-API quotes (once your Amazon account is connected), use Alexandria's sourcing chat.

The Alexandria way

Want this run on every ASIN you're considering?

Alexandria's sourcing chat runs the FBA vs FBM math per ASIN with our canonical 2026 fee model (live SP-API quotes once your Amazon account is connected) and tells you which fulfillment model wins on each product. Free, no signup.

Try the sourcing chatFreight calculator

Frequently asked questions

What's the difference between FBA and FBM on Amazon?

FBA (Fulfillment by Amazon) means Amazon stores your inventory, picks/packs/ships every order, and handles customer service. You pay a per-unit fulfillment fee plus monthly storage. FBM (Fulfillment by Merchant) means YOU store, pack, and ship every order yourself. You pay no FBA fees but you pay shipping, handling, and your own time. Most sellers default to FBA for the Prime badge and time savings; FBM wins on heavy/oversize items, low-velocity SKUs, or when storage fees would eat your margin.

Is FBA more profitable than FBM?

It depends on the SKU. For lightweight, fast-moving products under $25, FBA usually wins on per-unit margin AND saves you the labor. For heavy, slow-moving, or oversize items where storage fees pile up and FBA fulfillment fees spike, FBM almost always wins. The calculator above compares both side-by-side using current 2026 fee data — no guessing.

When should I use FBM instead of FBA?

Four common cases: (1) Oversize items over 20 lb where FBA fulfillment fees jump above $10/unit. (2) Slow-velocity SKUs that would sit 60+ days and rack up storage fees. (3) Items with high return rates where FBA's automatic refund processing costs you money. (4) Brand-gated categories where you can't get an FBA shipping plan approved but can ship direct.

Does FBM lose the Prime badge?

By default, yes — FBM listings don't get the Prime badge, which can drop conversion 15–30% on Prime-eligible categories. The exception is Seller Fulfilled Prime (SFP), which lets approved sellers ship FBM with the Prime badge if they meet strict 2-day delivery and performance metrics. SFP is hard to qualify for and adds operational overhead, but it's the only way to keep Prime while staying FBM.

How accurate is this FBA vs FBM calculator?

It uses Amazon's published 2026 fee schedule for FBA (Alexandria's canonical model, unit-tested for parity) and US national-average ground shipping rates for FBM. Accurate within ~10% for most SKUs. For ASIN-specific numbers, use Alexandria's chat — and once you connect your Amazon account, the chat pulls live SP-API quotes per ASIN with your real shipping discount.