Amazon FBA Cost Structure: How to Price Products for Profitability

Amazon FBA fees fall into three categories: fulfillment fees (picking, packing, shipping your item to the customer), storage fees (holding your inventory in Amazon's warehouse), and referral fees (Amazon's commission on each sale). All three are mandatory and must be modeled before you set a price.

There is also a fourth category of situational fees — removal/disposal, returns processing, inventory placement, unplanned service (mislabeled shipments) — that do not appear in every P&L but can materially impact margin if you are not paying attention.

Amazon updates its fee schedule annually, typically in January-February. The figures below reflect 2025 rates. Always verify current rates in Seller Central under the FBA Revenue Calculator or the fee schedule page before making pricing decisions.

Fulfillment fees are based on the product's size tier, determined by the greater of actual weight and dimensional weight. The main tiers as of 2025:

Small standard (≤ 4 oz, ≤ 15×12×0.75 in): $3.06 per unit. Large standard (≤ 1 lb): $3.58 per unit. Large standard (1–2 lb): $4.75 per unit. Products over 2 lbs add approximately $0.38–0.42 per additional pound.

Oversized tiers (any dimension exceeds 18×14×8 in, or weight exceeds 20 lbs) jump significantly: Small oversize starts at $9.73 per unit; large oversize can exceed $75 per unit for the heaviest items.

Dimensional weight applies when volume ÷ 139 exceeds actual weight (in pounds). A light but bulky item like a pillow or yoga mat often gets charged at dimensional weight, not actual weight. Always calculate both and use the higher number when planning.

Monthly storage fees are charged per cubic foot of space used. Off-peak months (January–September): approximately $0.87/cubic foot for standard-size, $0.56 for oversize. Peak months (October–December): rates roughly double to $2.40/cubic foot for standard, $1.40 for oversize.

The October–December storage spike catches new sellers off guard. A product that costs $0.10/unit to store in August costs $0.28/unit to store in November for the same inventory level. Factor this into Q4 pricing and avoid overstocking at peak rates.

Long-term storage fees (LTSF) apply to inventory that has been in an Amazon fulfillment center for more than 365 days. As of 2025, the charge is $6.90 per cubic foot per month (or $0.15 per unit, whichever is greater) for items stored over 365 days. LTSF is extremely expensive — remove or liquidate slow inventory well before the 365-day threshold.

Inventory Performance Index (IPI) score affects storage limits. Sellers with IPI below Amazon's threshold (currently 400) face storage volume restrictions during peak season. Maintain IPI above 450 to avoid restrictions.

Amazon charges a referral fee as a percentage of the total sales price (including shipping and gift wrap) on each sale. Rates vary by category: Home & Kitchen 15%, Electronics 8%, Clothing & Accessories 17%, Beauty & Personal Care 8–15%, Grocery & Food 8–15%, Health & Personal Care 8%.

The FBA Revenue Calculator (available free in Seller Central and as a Chrome extension) automates fee calculations. Enter your ASIN or product dimensions, selling price, and COGS — it outputs net proceeds after all FBA fees. Use this tool for every product before you source it.

Other fees to watch: Returns processing fee (charged when return rate exceeds category average, typically $2–5 per unit), Inventory placement service fee (if you do not want to ship to multiple warehouses, Amazon charges ~$0.30–$1.30 per unit to consolidate), Aged inventory surcharge (applied to items 181–365 days old, at lower rates than LTSF but still adds up).

A common profit model mistake: sellers calculate margin based on selling price minus COGS and FBA fulfillment fee, forgetting referral fees. On a $30 product in Home & Kitchen, the referral fee alone is $4.50. Include it in every unit economics calculation.