How to Calculate Amazon FBA Profit (Complete Guide)

Amazon FBA profit isn't just revenue minus product cost. Multiple fees eat into your margins at different stages, and missing even one can turn a profitable product into a loss maker.

The Complete FBA Profit Formula

Net Profit = Selling Price − All Costs

Where All Costs includes:

• Cost of Goods Sold (COGS)
• Inbound shipping to FBA
• Amazon referral fee (8-15% depending on category)
• FBA fulfillment fee (based on size/weight)
• Monthly storage fee
• Advertising cost per unit
• Returns handling and other misc costs

Step-by-Step Calculation

1. Start with Your Selling Price

This is what the customer pays. Note: Amazon calculates fees on the total item price including gift wrap, excluding tax.

2. Subtract Product Cost

Your COGS from the supplier, including freight to your prep center.

3. Calculate Amazon Referral Fee

Most categories charge 8-15%. Check your specific category in Seller Central.

4. Add FBA Fulfillment Fee

Based on product size tier and weight. Standard size small items are typically $3.22-$5.75.

5. Include Storage Costs

Monthly storage rates vary by season. Add estimated storage cost per unit.

6. Account for Advertising

If you run PPC campaigns, divide total ad spend by units sold to get cost per unit.

7. Calculate Net Profit

Subtract all costs from your selling price.

Example: Bluetooth Earbuds

Common Mistakes to Avoid

1. Forgetting inbound shipping — adds 5-15% to your cost base
2. Ignoring return rate — a 10% return on a 15% margin product destroys profitability
3. Overlooking peak storage rates — October-December rates are 2-3x higher
4. Counting ad spend separately — include it in per-unit economics from day one
5. Using last year's fee rates — Amazon revises fees annually

Tools to Help

Our Amazon FBA Profit Calculator walks through each line item and shows you the exact numbers for your product.

This guide was updated September 2026. Fee rates change annually — always verify current rates in Seller Central.