Calculate your Amazon seller profit after FBA fees, referral fees, advertising spend, and shipping costs. See net profit and margin per unit.
Knowing your true profit per unit on Amazon requires accounting for every cost: product cost, shipping to Amazon, FBA fulfillment fees, referral fees, advertising spend, and any other expenses. Many sellers focus only on the product cost and sale price, dramatically overestimating their actual margins.
This comprehensive profit calculator takes all major Amazon seller costs into account to give you an accurate net profit and margin per unit. It is designed for FBA sellers who want a clear picture of their unit economics before and after advertising.
Whether you are evaluating a new product opportunity or auditing an existing listing, entering realistic numbers here will reveal your true bottom line. Use it to set minimum sale prices, maximum ad budgets, and target margins that keep your Amazon business profitable. Whether you are a beginner or experienced professional, this free online tool provides instant, reliable results without manual computation. By automating the calculation, you save time and reduce the risk of costly errors in your planning and decision-making process.
Amazon selling involves many layered fees that can erode margins quickly. This calculator consolidates all costs into a single view, making it easy to spot whether a product is truly profitable or if you are losing money after all fees. It is especially useful during product research and during quarterly profit reviews.
Total Revenue = Sale Price Total Costs = Product Cost + Shipping to FBA + Referral Fee + FBA Fee + Ad Cost per Unit Net Profit = Total Revenue − Total Costs Profit Margin = (Net Profit / Sale Price) × 100 ROI = (Net Profit / Total Costs) × 100
Result: Net Profit: $13.49 per unit | Margin: 38.6%
Sale price $34.99. Referral fee: $34.99 × 15% = $5.25. FBA fee: $4.75. Product cost: $7. Shipping to FBA: $1.50. Ad cost: $3.00. Total costs: $21.50. Net profit: $34.99 − $21.50 = $13.49. Margin: $13.49 / $34.99 = 38.6%. ROI = $13.49 / $21.50 = 62.7%.
Amazon seller profitability depends on understanding every cost layer. The product cost and Amazon fees are obvious, but many sellers overlook inbound shipping, labeling, prep fees, returns, and the opportunity cost of capital tied up in inventory. A thorough per-unit cost analysis is the foundation of a profitable Amazon business.
Advertising is increasingly essential on Amazon. Most new products need significant ad spend to gain visibility and reviews. The key metric is ACoS (Advertising Cost of Sales) — the ratio of ad spend to ad revenue. A sustainable ACoS depends on your margins; if your pre-ad margin is 40%, your break-even ACoS is 40%.
As you scale, negotiate better supplier pricing, optimize packaging to reduce dimensional weight, improve ad efficiency through better targeting, and diversify across multiple products to spread fixed costs. The most profitable Amazon businesses are those that continuously optimize every cost line item.
Most successful Amazon sellers target 20–35% net margin after all fees. Below 15% is risky because fee increases, competition, or returns can quickly turn a profit into a loss. Top sellers often achieve 30%+ through efficient sourcing and advertising.
Divide your total advertising spend for a period by the total number of units sold in that period. For example, if you spent $500 on ads and sold 200 units, your ad cost per unit is $2.50. Include all ad types: Sponsored Products, Brands, and Display.
Use total units sold (organic + ad-driven) to get an accurate per-unit ad cost. Advertising increases your organic visibility too, so spreading the cost across all units gives a more realistic picture of your true advertising cost.
Common overlooked costs include shipping to FBA, product inspection fees, packaging and labeling, product photography, long-term storage fees, return processing, and profit lost on returned/damaged items. Including these gives a more realistic profit picture.
Profit margin is net profit divided by sale price (revenue-based). ROI is net profit divided by total costs invested (investment-based). A 30% margin might represent a 75% ROI. ROI tells you how efficiently your invested capital generates profit.
Review unit economics monthly at minimum. Costs change frequently — Amazon updates fees annually, supplier costs fluctuate, and advertising costs vary with competition. Quarterly deep reviews help catch margin erosion before it becomes critical.