How to Calculate Profit Margins for an Amazon FBA Business

Selling products through Amazon FBA (Fulfillment by Amazon) is incredibly appealing. You source the products, ship them to Amazon's warehouse, and Amazon handles the storage, shipping, and customer service. It feels like a passive income dream.

However, the reality is that Amazon FBA is a razor-thin margin business. Many sellers see their dashboard show $10,000 in sales for the month, only to realize their bank account actually went down.

To survive on Amazon, you must ruthlessly calculate your profit margins.

Gross Margin vs. Net Margin

When calculating your Amazon profits, you have to distinguish between two different types of margins:

Gross Margin: The revenue left over after subtracting the direct cost of the physical product (COGS).
Net Margin: The final profit left over after subtracting everything—including Amazon's fees, advertising, and your monthly software subscriptions.

The Hidden FBA Fees

Amazon takes a massive cut of your sales to cover their world-class logistics network. When calculating your Net Margin, you must account for all of these deductions:

Referral Fee: Amazon takes a flat percentage of the sale price just for letting you sell on their platform. For most categories, this is 15%.
FBA Fulfillment Fee: A flat fee to pick, pack, and ship your item. This depends entirely on the size and weight of your product. A small, lightweight item might cost $3.00 to ship, while a heavy item could cost $15.00.
Storage Fees: Amazon charges you a monthly fee based on the cubic volume of your inventory sitting on their shelves. This fee quadruples during the Q4 holiday season!

A Real-World Example

Let's look at the math for selling a single Garlic Press.

Retail Price: $20.00
Cost of Goods (Manufacturing + Shipping from China): -$4.00
Your Gross Profit is $16.00 (An 80% Gross Margin!)

Now let's apply the FBA reality:

Amazon Referral Fee (15%): -$3.00
FBA Fulfillment Fee: -$3.50
PPC Advertising Cost (to get the sale): -$4.00
Final Net Profit: $5.50

Your actual Net Profit Margin is 27.5%. While that is still a healthy margin for e-commerce, it is a far cry from the 80% you started with.

Don't Source Blindly

Never order inventory from a supplier until you have meticulously modeled the margins. Use our free Profit Margin Calculator to quickly punch in your expected sale price and costs, ensuring your new product idea is actually financially viable!