Amazon FBA Profit Calculator

How to Calculate Amazon FBA Profit

Your Amazon FBA profit per unit is what remains from your selling price after deducting every cost involved in getting that unit sold and delivered. The complete formula is: Net Profit = Selling Price − COGS − Referral Fee − FBA Fulfillment Fee − Inbound Shipping ± Optional Costs.

The referral fee is Amazon's marketplace commission — typically 15% for most categories, 8% for electronics, and 17% for clothing. It's calculated as a percentage of your selling price, not your profit. The FBA fulfillment fee covers picking, packing, shipping to the customer, and customer service. It ranges from ~$3.06 for a small light item to $6+ for a heavier standard-size product. Use our Amazon FBA Fee Calculator to estimate your exact fees before entering them here.

Inbound shipping to Amazon is a cost many beginner sellers forget. Every unit you ship from your supplier to Amazon's fulfillment centers costs money — whether via air freight, sea freight, or domestic LTL. This should be included in your per-unit cost to get an accurate profit figure. Our Landed Cost Calculator can help you calculate the true per-unit sourcing cost including freight, duty, and customs.

Understanding Margin, ROI, and Break-Even ACoS

Margin % (also called profit margin) tells you what percentage of each sale you keep as profit. A 25% margin means for every $100 in sales, $25 is profit. Most experienced FBA sellers target 20–30%+ margin. Below 15%, you have very little buffer for fee increases, PPC costs, or unexpected returns. At 10% or below, most products become unviable once you factor in advertising.

ROI % (Return on Investment) measures how efficiently your capital is working. A 50% ROI means you get back $1.50 for every $1.00 you invest in inventory. ROI is calculated on your invested capital (COGS + inbound shipping) rather than revenue. Experienced FBA sellers typically target 30–50%+ ROI to justify the operational risk, though the right target depends on how fast your inventory turns. Use our ROI Calculator for a focused analysis.

Break-Even ACoS (Advertising Cost of Sale) is the maximum percentage of ad revenue you can spend on ads before advertising makes you unprofitable. It equals your gross margin before advertising costs. If your break-even ACoS is 22% and your actual ACoS is 18%, your ads are profitable. If your ACoS exceeds break-even, every advertised sale loses money. Use our PPC ACoS Calculator to analyze your advertising profitability in depth.

The Hidden Costs Most Sellers Miss

The optional inputs in this calculator exist because the most common FBA profit mistake is only modeling referral fees and fulfillment fees while ignoring the costs that silently erode margin over time.

Storage fees accumulate every month your inventory sits in Amazon's warehouses. A $0.87/cubic foot monthly rate (Jan–Sep) can add $0.10–$0.30 per unit for a typical-size product — and that triples to $2.40/cu ft during Q4 peak season (October–December). Slow-moving products can become negative-margin propositions purely from storage. Our Storage Fee Calculator gives you the exact monthly figure to plug in here.

PPC / advertising spend is often the largest hidden cost for growing FBA sellers. If you spend $2 per unit on ads, that $2 comes directly out of your margin. Entering your average cost-per-unit from advertising shows your true net margin after ads — the number that matters for sustainable profitability, not just organic margin.

Return rates vary by category — apparel and electronics see 15–30% return rates while simpler products run 2–5%. Every return costs you both the profit you expected to make plus the return processing fee Amazon charges. A 5% return rate on a $3.00 profit product can drop effective profit by $0.30–$0.40 per unit sold — significant at scale. Use our Return Impact Calculator for a detailed analysis.

Frequently Asked Questions