AMAZON SELLER TOOL
FBA Profit Margin Calculator
Enter sale price, COGS and FBA fees to calculate Amazon per-unit profit margin and monthly total profit. 100% local processing, no data uploaded.
Enter sale price, COGS and FBA fees to calculate Amazon per-unit profit margin and monthly total profit. 100% local processing, no data uploaded.
Amazon FBA (Fulfillment by Amazon) lets you store products in Amazon warehouses, where Amazon handles picking, packing, shipping, customer service, and returns. While this removes operational headaches, it also introduces a complex web of fees that make it difficult to know your true profit per unit. Many sellers look at their dashboard revenue and assume they are doing well, only to discover at the end of the month that FBA fulfillment fees, referral commissions, storage charges, and advertising costs have eaten most of their margin. This calculator breaks down every cost component so you can see exactly what you keep.
Amazon deducts several fees from each sale before sending you the net proceeds. Understanding each one is essential for accurate profit calculation:
The core profit formula strips away Amazon fees from your selling price to reveal what you actually earn:
Net Profit = Selling Price - Product Cost - Shipping to FBA - Referral Fee - FBA Fulfillment Fee - Storage Fee - PPC Ad Cost - Returns Reserve
From there, two key metrics are derived:
Net Margin % = (Net Profit / Selling Price) x 100
ROI % = (Net Profit / Total Investment) x 100
Total Investment includes product cost, shipping to Amazon, and any upfront costs like photography or listing optimization. A 100% ROI means you double your investment on every unit sold.
Suppose you sell a silicone kitchen gadget for $24.99. Your product cost from the factory is $4.50, shipping to Amazon FBA warehouses costs $1.20 per unit, and the product is a Standard-size item weighing 0.3 lb. Let us calculate the profit:
Step 1 - Referral Fee: $24.99 x 15% = $3.75
Step 2 - FBA Fulfillment Fee: Standard size, 0.3 lb = $3.39 (per current Amazon fee schedule)
Step 3 - Storage Fee: Estimated $0.05 per unit per month (small Standard-size item)
Step 4 - PPC Ad Cost: Assuming 25% ACoS, ad cost per unit = $24.99 x 25% x (ad-driven sales ratio). Simplified: about $3.00 per unit.
Step 5 - Returns Reserve: Estimated 5% return rate, reserve = $24.99 x 5% = $1.25
Step 6 - Net Profit: $24.99 - $4.50 - $1.20 - $3.75 - $3.39 - $0.05 - $3.00 - $1.25 = $7.85
Step 7 - Net Margin: $7.85 / $24.99 = 31.4%. This is a healthy margin. The ROI is $7.85 / ($4.50 + $1.20) = 138%, meaning you earn $1.38 for every $1.00 invested in inventory and shipping.
Enter your selling price, product cost per unit, and inbound shipping cost. Select your product's size tier (Standard or Oversize) and enter its weight. The calculator auto-fills the referral fee based on your category. Add your PPC ACoS percentage and expected return rate. The tool instantly shows total costs, net profit, net margin, and ROI. Adjust any input to model different pricing scenarios.
Each FBA sale incurs a referral fee (typically 15% of sale price, varies by category), an FBA fulfillment fee (pick and pack, based on size tier and weight, starting around $3.06 for Standard-size), and a monthly storage fee ($0.87 to $2.40 per cubic foot depending on season). Additional costs include PPC advertising and a returns reserve.
A healthy net profit margin for Amazon FBA is 20-30%. Products under 15% net margin are risky because any increase in PPC costs, fee changes, or returns can push them into a loss. Aim for 25% or higher to build a sustainable business that can absorb fee increases and seasonal fluctuations.
Gross margin is (Revenue - Product Cost) / Revenue, covering only the direct cost of goods. Net margin subtracts ALL costs including FBA fees, referral fees, PPC advertising, storage, and returns. Net margin is the percentage you actually keep, and it is the number that determines whether your product is viable long-term.
ROI = (Net Profit / Total Investment) x 100. Your investment includes product cost, shipping to Amazon, and any upfront costs. A 100% ROI means you double your money on each unit sold. Most experienced sellers aim for 100% or higher ROI on new products, and will discontinue items below 50% ROI unless they serve a strategic purpose.
Amazon classifies every FBA product into a size tier based on its packaged dimensions and weight. Standard-size items (under 18x14x8 inches and under 20 lb) have lower fulfillment fees. Oversize items (Large Bulky, Extra Large, or Special Oversize) have progressively higher fees. A product that crosses from Standard to Small Oversize can see its fulfillment fee jump by $5-15 per unit.
Yes. Most categories charge 15%, but it ranges from 8% (certain consumer electronics and Amazon devices) to 45% (media products like books and DVDs). Beauty, health, and baby products are 15%. Clothing and accessories are 17%. Always verify the referral fee for your specific category on Amazon's official fee schedule before pricing your product.
Absolutely. PPC ad spend is a real cost of selling on Amazon. New sellers often underestimate it, but most products require 15-30% ACoS to maintain visibility. If your product sells for $25 and your ACoS is 25%, you are spending roughly $3-6 per unit on ads depending on the organic-to-ad sales ratio. Always include this in your profit calculation.