Amazon FBA Profit Calculator

What are Amazon FBA fees?

Amazon FBA (Fulfillment by Amazon) is the service in which Amazon stores your inventory, picks and packs orders, ships them, and handles customer service and returns. In exchange, FBA charges a stack of fees on every unit you sell — fees that come straight off the top before you see any of the sale revenue.

The three core FBA charges are the referral fee (typically 15% of the sale price, varies 6–17% by category), the FBA fulfillment fee (a flat per-unit fee that scales with size and weight — small standard items run roughly $3.22, large standard $5–9, oversize $10+), and storage fees ($0.83 per cubic foot per month off-peak, jumping to $2.40 during October-December for crowded items).

Add a typical 5–15% return rate (returns get refunded but you keep the FBA fee, and the unit often becomes unsellable), and total FBA-related costs commonly run 25–40% of revenue for standard-size goods. That's why FBA arbitrage works best on products with at least a 3× markup over landed cost.

How to calculate Amazon FBA profit

Net profit per FBA unit subtracts every variable cost from the sale price. The formula breaks down as:

Formula: Profit = Price − (Price × Referral%) − FBA fulfillment fee − Storage − Product cost − Inbound shipping − Returns adjustment

Where the referral percentage depends on category (15% for most home/electronics/beauty, 8% for personal computers, 17% for accessories), FBA fulfillment fee comes from Amazon's size-tier chart, storage is the per-unit share of your monthly cubic-foot bill, and the returns adjustment is roughly Return Rate × (Refund + FBA processing + Damage).

Worked example. A US seller sources a $7 kitchen gadget from a supplier, ships it to Amazon for $0.85 per unit, and lists at $24.99. Standard-size FBA fee: $4.75. Monthly storage allocation: $0.30. Referral fee at 15%: $3.75. Return rate 8%, refund cost about $3 per returned unit on average. Profit per unit = $24.99 − $3.75 − $4.75 − $0.30 − $7.00 − $0.85 − ($3 × 0.08) = $8.10 per unit (32.4% margin).

At 200 units sold per month, that's $1,620 profit per month from one SKU before income tax. The same math at $19.99 sell price drops profit to roughly $4.35 per unit — a 5-dollar price drop nearly halves the profit. This is why list-price selection is the single most consequential decision in FBA.

How to use this calculator

Pick your marketplace at the top — it auto-fills referral and FBA fees in the correct currency for US, UK, DE, CA, JP and AU. Enter the sale price (your Amazon listing price), product cost (what you pay your supplier per unit, landed), inbound shipping cost (per-unit cost to send to Amazon's warehouse), and select the size tier (small standard, large standard, or oversize — check the Amazon listing photo dimensions if unsure).

Add a realistic return rate (5–8% for apparel-free goods; 15–25% for clothing or anything subjective like fragrance) and a monthly storage cost per unit (your inventory's cubic feet × $0.83 ÷ monthly units sold). Toggle "Include shipping" if the buyer pays shipping. The advanced section overrides referral% and FBA fee defaults for category exemptions. Results show total fees, net profit, profit margin, and the per-unit profit you'd actually book.

Real-world examples

Example 1 — Standard kitchen gadget, healthy margins. $24.99 sell price, $7 product cost, $0.85 inbound, standard size ($4.75 FBA fee), 15% referral ($3.75), $0.30 storage, 8% returns. Profit per unit: $8.10 (32% margin). At 200 units/month: $1,620/month profit. Returns are manageable because kitchen tools don't get returned often. This is the FBA sweet spot — sub-$10 sourcing on a $25 list price.

Example 2 — Apparel item, return-heavy. $35 T-shirt design, $11 product cost (Printful via FBA), $1.50 inbound, large standard FBA fee $5.45, 15% referral ($5.25), $0.40 storage, 22% return rate (apparel norm — wrong size, didn't like fit). Profit per unit if no returns: $11.40. Adjust for 22% return rate at $4 average return cost: −$0.88. Final profit: $10.52 (30% margin). At 80 units/month: $842/month profit. Workable but apparel's high return rate means net cash flow is more volatile than the unit math suggests.

Example 3 — Oversize home product, thin margin. $49 doormat, $18 product cost, $3 inbound, oversize FBA fee $10.50, 15% referral ($7.35), $1.20 storage (heavier item = more cubic feet), 4% return rate at $5 each. Profit: $49 − $7.35 − $10.50 − $1.20 − $18 − $3 − $0.20 = $8.75 per unit (17.8% margin). Functional but every variable matters — a $1 supplier price hike eats 11% of the margin instantly. Compare against the Amazon Revenue Calculator to see whether monthly volume justifies the working capital tied up in oversize inventory.

Common mistakes and benchmarks

The biggest FBA mistake is underestimating returns. New sellers often plug 2–3% return rate into spreadsheets when the real number for their category is 5–8% (general merchandise) or 15–25% (apparel, supplements, anything subjective). Amazon keeps the referral fee on returned orders and charges a return processing fee — a 20% return rate easily eats 4–8% of gross margin.

Second is ignoring long-term storage fees. Inventory sitting in Amazon warehouses for 271+ days triggers an aged-inventory surcharge of $6.90 per cubic foot per month. Slow-moving SKUs get expensive fast — three months of aged inventory on 50 units of a half-cubic-foot item is $517 in surcharges alone.

Healthy benchmarks. Target gross margin above 30% after all fees and returns. Net profit per unit at least $3 (anything less can't survive ad costs). Aim for 3× markup minimum over landed cost (sell at 3× what you paid all-in). Inventory turn (units sold ÷ average inventory) should hit 4–6 per year minimum — slower turn means too much capital trapped in storage. Use the Amazon Seller Calculator to see the full-business view including ads and overhead.