For Amazon FBA Sellers Who Import Products
See your true cost
from factory to customer.
Finally.
Most Amazon sellers overestimate their margins by 30-50%. MarginStack reveals every hidden cost between your supplier's invoice and your actual profit, including duties, freight, and Amazon's cut.
The margin you calculate is not the margin you keep.
Most sellers calculate margin as: Selling Price minus Product Cost minus Amazon Referral Fee. That misses freight, customs duties, brokerage fees, FBA fulfillment, and storage costs. The result? For a 500ml stainless steel vacuum insulated flask from China, you think you're making 56%. You're actually making 33% (rates as of 24 July 2026).
WHAT MOST SELLERS CALCULATE
3 line items. Looks great. Feels profitable.
WHAT MARGINSTACK SHOWS YOU
$8.18 per unit you didn't know you were losing.
Your complete cost waterfall, in seconds.
Enter your product details. MarginStack calculates duties, freight, and Amazon fees, then shows you exactly where every dollar goes.
Example Product
500ml stainless steel vacuum insulated flask
Imported from China, sold at $34.99, rates as of 24 July 2026
True Margin
$11.56
33.0%
Full Cost Calculator
Enter your product details and get a complete cost breakdown in seconds. FOB, freight, every duty layer in force (MFN Base Duty, Section 232 (National Security), Section 301 (Forced Labor) and Section 301 (China lists)), Amazon referral, FBA fulfillment, and storage. Nothing hidden.
Open CalculatorCountry Comparison
Compare landed cost across China, Vietnam, India, Mexico, and Thailand side-by-side. See exactly how sourcing country affects your duties, freight, and true margin.
Compare CountriesDuty Stack Explained
Understand exactly how MFN Base Duty, Section 232 (National Security), Section 301 (Forced Labor) and Section 301 (China lists) stack on top of each other. Plain English, no legal jargon.
Learn About DutiesWhat MarginStack includes that other calculators don't
Amazon's own calculator and the popular seller tools stop at Amazon fees. None of them account for import duties, freight, or customs costs.
| Cost layer | Amazon | Jungle Scout | Helium 10 | MarginStack |
|---|---|---|---|---|
| Amazon referral fee | ||||
| FBA fulfillment fee | ||||
| Monthly storage fee | ||||
| Inbound placement fee | ||||
| Ocean / air freight | ||||
| MFN Base Duty | ||||
| Section 232 (National Security) | ||||
| Section 301 (Forced Labor) | ||||
| Section 301 (China lists) | ||||
| Customs brokerage | ||||
| Country sourcing comparison |
Comparison based on free tier features of each tool as of February 2026.
Stop guessing. Start calculating.
Your competitors are pricing based on incomplete data. Know your true cost, set your price with confidence.
Calculate Your True MarginFree for your first 5 calculations. No credit card. No signup.