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Amazon FBA Calculator
Before you order a single unit, find out if the product actually makes money. Enter your price, cost, and Amazon's fees to see your net profit per unit, your margin, and your return on cost — the numbers that decide whether a product is worth sourcing.
Start from a template
→ Your FBA profit
You net $10.29 per unit
Amazon fees eat 46% of the sale price here. FBA sellers typically target a 25–35% margin and at least a 100% return on cost (roughly a 3× sell-to-cost ratio) to survive PPC and price competition. Below that, one advertising bump or fee increase can wipe out the profit.
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An estimate for planning. Amazon fees vary by category, size, and season — confirm current fees in Seller Central before committing to a product.
Where the money goes on an FBA sale
The sticker price is not what you keep. Amazon takes a referral cut of every sale, charges a flat fee to pick, pack, and ship each unit, and — for most sellers — the real profit killer is the advertising it takes to get seen. Add the landed cost of the product itself and the inbound freight to Amazon's warehouses, and a $30 sale often leaves single-digit dollars of profit. Costing a product honestly, before you commit inventory capital, is what separates FBA businesses that scale from the ones that stall on a garage full of unsellable stock.
The per-unit formula
- Amazon fees = referral (price × %) + FBA fee + inbound shipping + PPC/other
- Net profit = price − product cost − Amazon fees
- Margin = net profit ÷ price; ROI = net profit ÷ product cost
Take a $29.99 product costing $6 landed. A 15% referral is $4.50; add a $5.50 FBA fee, $1.20 shipping, and $2.50 of PPC and you're at $13.70 in fees. Net profit is about $10.29 — a 34% margin and a 172% return on cost. Healthy — but drop the price to compete, or watch PPC creep up, and that cushion thins fast.
Margin and ROI are both the point
Margin measures profit per sale; ROI measures how quickly your cash comes back to reinvest. A product with a great margin but a high unit cost ties up capital between reorders, while a cheaper unit with the same margin recycles your cash faster — letting you restock, rank, and grow sooner. FBA rewards sellers who watch both, because running out of stock on a ranked listing is as costly as a thin margin.
From unit economics to a fundable brand
A profitable unit is the foundation; a business needs volume, inventory planning, and a marketing engine on top. If you're raising money or applying for financing to scale an e-commerce brand, these per-unit numbers become the base of the model — pair them with the profit margin calculator for the blended picture and the startup financial model to project the whole business forward.
→ Beyond the calculator
Raising money for an e-commerce brand?
Unit economics are the foundation of an e-commerce plan. Our business plan writers turn your margins and growth plan into the funding-ready document a lender or investor expects.
Frequently asked questions
- Net profit per unit = sale price − product cost − Amazon fees, where fees include the referral fee (a percentage of the sale price, usually 15%), the FBA fulfillment fee (a flat per-unit charge by size and weight), inbound shipping, and your advertising and other per-unit costs. What's left is your profit; divide it by the sale price for margin, or by product cost for ROI.
- The two big ones are the referral fee (about 15% of the sale price for most categories) and the FBA fulfillment fee (a flat charge per unit based on size and weight). On top of those come monthly storage fees, long-term storage fees, returns processing, and — for most sellers — significant PPC advertising spend, which is why it's included here as a per-unit cost.
- Most successful FBA sellers target a 25–35% net margin and at least a 100% return on cost (roughly a 3× sell-price-to-cost ratio). That cushion has to absorb PPC, returns, fee increases, and price competition. Thinner margins can work at high volume, but they leave little room for the ad spend it usually takes to rank.
- Margin tells you profit per sale; ROI tells you how fast your cash recycles. A 30% margin product that costs $6 returns your capital far quicker than one that costs $40, letting you reinvest in inventory sooner. FBA is a cash-flow game as much as a margin game, so sellers watch both.
- Yes — it runs in your browser, nothing is stored, and there's no sign-up. Fees vary by category and season, so confirm current figures in Seller Central. When you're raising money or planning an e-commerce brand, our business plan writers turn these unit economics into a fundable plan.