Amazon FBA Calculator

What it does

Amazon FBA (Fulfilled by Amazon) seller fees stack into three components that determine whether a product is profitable to sell on the platform: the referral fee (Amazon's cut, typically 8-15% of sale price depending on category — 15% for most consumer categories, 8% for electronics with caps, 12% for home goods, 17% for jewelry over $250), the FBA fulfillment fee (Amazon picks your inventory, packs it, ships to the customer — fee scales by package size and weight: small items $3.20-4.30, medium $5-8, large $9-15, oversized $25-95+), and the monthly storage fee ($0.87-2.40 per cubic foot per month, with surcharges for long-term storage past 270 days). Plus optional fees: removal fees if you pull inventory back, return processing fees, high-volume listing fees.

The calculator takes your sale price, cost of goods, category, and product dimensions/ weight, then breaks out every fee and shows your gross margin per unit, net profit per unit, and break-even sale price. Most FBA sellers' profitability is determined before they list — buying at the wrong cost (cost of goods over 30% of expected sell price) means even successful sales produce razor-thin or negative margins. Standard target: keep cost of goods under 30% of sell price for adequate margin after Amazon's ~30-40% effective fee load (referral + fulfillment + storage). So a $30 sell-price item should cost under $9 from your supplier for healthy economics.

Critical considerations the calculator surfaces: (1) Storage costs compound monthly — slow-moving inventory eats margin. Plan for 6-12 month sell-through; products that sit longer accumulate fees and trigger long-term storage surcharges (additional $6.90/cubic foot after 270 days). (2) Returns are a hidden cost — Amazon's generous return policy creates 5-15% return rates depending on category; many returned items are then unsellable. (3) PPC advertising on Amazon (Sponsored Products) is essentially mandatory for visibility — budget 5-15% of revenue for ads on top of fees. (4) ACoS (Advertising Cost of Sale) targets vary by margin; high-margin products can sustain higher ACoS. The realistic all-in cost stack for a typical FBA seller: 35-45% on Amazon fees + ads, before product cost. So gross margin target of 30%+ before ads is needed for sustainable business.

How to use it

1. Enter your sale price (Amazon listing price).
2. Enter cost of goods (what you pay your supplier).
3. Pick category — referral fee varies 8-17% by category.
4. Enter product dimensions and weight — drives FBA fulfillment fee.
5. Read the per-unit profit, margin %, and break-even price.
6. Compare to your inbound costs (shipping to Amazon, prep fees) for true landed margin.

When to use this tool

• Pre-launch product profitability analysis — confirm a product is worth selling before placing bulk inventory orders.
• Pricing decisions — finding the sweet spot between margin and competitive listing price.
• Comparing products in your potential lineup to prioritize the highest-margin opportunities.
• Tracking actual vs forecast margin after a quarter of sales data.
• Negotiating with suppliers — knowing your minimum acceptable cost-of-goods.

When not to use it

• Custom or made-to-order products — those use FBM (Fulfilled by Merchant) where you handle shipping; different fee structure.
• Multi-channel sellers — calculator targets Amazon-only economics; cross-channel needs broader analysis.
• International FBA expansion — fee structures differ in EU, UK, Japan, India marketplaces.
• Subscription / Subscribe-and-Save — those have additional fees and discount math.

Common use cases

• Onboarding a colleague who needs the same calculation/conversion
• Verifying a number or output before passing it on
• Quick calculation during a typical workday
• Pre-decision sanity-check on inputs and outputs