Amazon's own Revenue Calculator leaves out advertising cost, returns, and other real expenses — which is why sellers who rely on it alone are often surprised by their actual margin. Here's the full formula.
Margin % = Net Profit ÷ Selling Price × 100
AppStoma's Margin Calculator runs this exact formula automatically, with real referral fees, FBA rates, and GST/VAT handling for Amazon.in, Amazon.com, and Amazon.co.uk — not a generic US-only estimate.
Calculate your real margin →Add together: the referral fee (a percentage of selling price that varies 4%-20% by category), the FBA fulfillment fee (based on product weight and size tier), and any closing fee. Subtract this total, plus your product cost and ad spend, from your selling price to get net profit.
Most sellers target at least 20-30% net margin after all fees. Below 10-15% is considered thin and risky, since it leaves little room to absorb ad cost increases, returns, or price competition.
No — Amazon's official Revenue Calculator only includes referral and fulfillment fees, not advertising cost, returns, or storage fees. Sellers typically underestimate true costs by relying on it alone; a full margin calculation should add ad spend (commonly 5-15% of selling price) and other operating costs.
Fee percentages are approximate and vary by category and marketplace — always confirm current rates in Seller Central before pricing.