How to calculate your real margin on Amazon FBA Mexico

Many sellers look at the sale price and product cost, see a “healthy” gap and assume they’re winning. On Amazon FBA Mexico, between that price and your pocket sits a line of deductions that, together, eat the margin. Here’s the full formula.

Everything Amazon deducts

To reach your real margin, beyond product cost you must subtract:

• Referral fee: a percentage of the sale price, varying by category.
• FBA fee (fulfillment): per unit picked, packed and shipped, by weight and dimensions.
• Storage: monthly and, if your product lingers, long-term storage.
• Returns and refunds: a real cost, not an exception.
• Advertising (if you run Amazon Ads): ACoS comes out of your margin.
• Tax (IVA): 16% you must handle correctly.

The formula

Net margin = Price − Product cost − Referral − FBA − Prorated storage − Inbound shipping − % Returns − Applicable tax

The detail almost everyone forgets: shipping your inventory to Amazon’s center (inbound) and prorating storage per unit. On low-price products, those two decide whether you win or lose.

Simplified example

Item	Amount
Sale price	$499
Product cost	−$180
Referral (~15%)	−$75
FBA fee	−$70
Storage + inbound	−$25
Returns provision	−$20
Margin before Ads	$129 (26%)

If your target ACoS is 15% ($75), your real margin drops to ~$54. The gap between “26%” and “11%” is exactly what you don’t see in Amazon’s dashboard.

Why a spreadsheet isn’t enough

These numbers change weekly: fees, returns, warehouse occupancy. Computing it by hand for hundreds of SKUs is unfeasible and always lagging. Useful profitability is what you see today, per product, with everything deducted.

In short

Your real margin isn’t “price minus cost.” It’s what’s left after referral, FBA, storage, inbound, returns, Ads and tax. Seeing that number per product is the difference between growing and growing while losing. iqseller computes real net margin per product and channel, automatically.

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