Amazon FBA Fee Calculator 2025: Every Fee Explained With Examples

Selling on Amazon through FBA sounds simple until you see the fee breakdown. Between referral fees, fulfillment fees, storage fees, and occasional penalties, your margin can shrink faster than expected. This guide walks through every Amazon FBA fee in 2025 and shows you how to calculate true profit per unit.

The Two Big Fees Every Seller Pays

Referral fees are category-based commissions Amazon charges on every sale. Most categories sit at 15%, but electronics drop to 8% and accessories can hit 45%. This fee applies to the total selling price including shipping.

Fulfillment fees cover picking, packing, shipping, and customer service. These depend on your product’s size tier and weight. A small standard non-apparel item under 12 oz costs around $3.22 to fulfill, while large oversize items can exceed $90.

Hidden Fees That Eat Margin

Monthly inventory storage runs $0.87 per cubic foot January through September, then jumps to $2.40 during October through December. If inventory sits longer than 365 days, aged inventory surcharges apply. Returns processing fees hit specific categories like apparel and shoes.

Using the Calculator

Our Amazon FBA fee calculator lets you input product price, cost of goods, shipping to Amazon, weight, and category. It instantly shows referral fee, estimated fulfillment fee, and net profit per unit. Adjust your monthly units sold to see projected monthly profit.

Example: A $29.99 kitchen gadget in a 15% category, weighing 1.2 lb, with $8 COGS and $1.50 inbound shipping nets roughly $12.13 per unit after all FBA fees.

Tips to Reduce FBA Costs

• Design packaging to fit standard-size tiers, avoiding oversize penalties.
• Ship inventory in steady cadences to reduce storage spikes.
• Remove slow sellers before the 365-day aged inventory threshold.
• Bundle small items to spread fulfillment costs across multiple units.

Bottom Line

FBA remains the easiest way to offer Prime shipping, but fees can consume 25-40% of revenue depending on category and size. Model every SKU before ordering inventory. Use our calculator to avoid surprises and price for actual profit, not just revenue.