FBA vs FBM Comparison Calculator

About the FBA vs FBM Comparison Calculator

The FBA vs FBM Comparison Calculator helps Amazon sellers compare the total cost of using Fulfilled by Amazon (FBA) against Fulfilled by Merchant (FBM) for their products. FBA includes picking, packing, shipping, customer service, and returns handling, but comes with fulfillment fees and monthly storage fees that can significantly impact margins.

FBA fees are based on product size and weight: standard-size items cost $3.22–$6.90+ per unit, while oversize items cost $9.73+. Monthly storage is $0.87/cu ft (Jan–Sep) and $2.40/cu ft (Oct–Dec). FBM has no Amazon fulfillment fees but requires you to handle all shipping, which may cost more or less depending on your setup.

This calculator compares both options side-by-side so you can see the per-unit profit difference and decide which fulfillment method maximizes your margin for each product.

When This Page Helps

FBA offers convenience and Prime eligibility but can eat margins on lower-priced items. This calculator shows the exact profit difference between FBA and FBM so you can make data-driven fulfillment decisions for each SKU.

How to Use the Inputs

1. Enter the selling price and product cost.
2. Enter the product dimensions and weight for FBA fee calculation.
3. Enter the Amazon referral fee percentage (usually 15%).
4. Enter your FBM shipping cost per order.
5. Enter the monthly storage fee if using FBA.
6. Compare per-unit profit between FBA and FBM.

Example Calculation

Tips & Best Practices

• FBA gives you Prime badge, which typically increases conversion rate 20–50%.
• FBA storage fees spike 2.75× during Q4 (Oct–Dec) — plan inventory carefully.
• Products priced under $15 often lose money on FBA due to high relative fulfillment fees.
• Consider FBA for fast-selling items and FBM for slow-selling or oversized items.
• FBA handles customer service and returns, saving you 5–15 minutes per customer interaction.
• Use the FBA Revenue Calculator in Seller Central to get exact fee estimates for each ASIN.

FBA Fee Structure Explained

Amazon FBA fees include three components: per-unit fulfillment fees (pick, pack, ship), monthly storage fees (per cubic foot), and optional services (labeling, prep). Fulfillment fees range from $3.22 for small standard items to $9.73+ for large oversize items. Storage fees vary seasonally.

When FBM Wins Over FBA

FBM is typically more profitable for: oversized items where FBA fees are $10+, slow-moving inventory that accumulates storage fees, items priced under $12–15 where FBA fees eat most of the margin, and products you can ship cheaply via USPS First Class (under 1 lb).

Hidden Costs of Both Models

FBA hidden costs include inbound shipping to Amazon warehouses, removal/disposal fees for unsold inventory, and higher return rates. FBM hidden costs include your time (opportunity cost), customer service labor, return processing, and the lower conversion rate without Prime eligibility.

Frequently Asked Questions

• What is the FBA fulfillment fee?

  FBA fees depend on size and weight. Standard-size (under 20 lbs): $3.22 for small items up to $6.90+ for heavier items. Oversize items start at $9.73. Fees include pick, pack, and ship. Check Amazon's current fee schedule as rates change annually.

• What are FBA storage fees?

  Monthly storage is charged per cubic foot of space your inventory occupies in Amazon's warehouse. Standard rates are $0.87/cu ft (Jan–Sep) and $2.40/cu ft (Oct–Dec). Items stored over 181 days incur a low-inventory-level fee, and over 365 days incur aged inventory surcharges.

• Is FBA always better than FBM?

  No. FBA is typically better for: small/lightweight products, fast-selling items, Prime-eligible listings. FBM may be better for: oversized items (high FBA fees), slow-turning inventory (high storage fees), very low-priced items, and products you can ship cheaply with negotiated rates.

• Can I use both FBA and FBM?

  Yes, many sellers use a hybrid approach. Ship fast-selling standard-size items via FBA for the Prime badge, and fulfill oversized, slow-selling, or low-margin items via FBM. You can also use FBM as a backup when FBA inventory runs low.

• How does FBA affect conversion rate?

  Products with the Prime badge typically see 20–50% higher conversion rates and often win the Buy Box more frequently. This sales velocity increase may offset higher FBA fees. Factor in the revenue impact, not just the cost difference.

• What about FBA returns?

  Amazon handles FBA returns for free (to you), but charges return processing fees for certain categories (apparel, shoes). The return rate on FBA is typically 5–15% higher than FBM because Amazon makes returns very easy for customers.