How to Calculate Import Duties for eCommerce Sellers

A practical guide for online sellers who source products internationally.

Why eCommerce Sellers Must Understand Import Duties

If you sell physical products on Amazon, Shopify, eBay, or any online platform, and those products are manufactured outside the United States, you are an importer. That means you are legally responsible for paying customs duties, and those duties directly affect your profit margins.

Too many eCommerce sellers calculate their product cost as “supplier price + shipping” and call it done. They then discover, often after hundreds of units are already in transit, that duties, fees, and tariffs add 15–40% to their actual cost. This guide walks you through every step of calculating your true import cost.

Step 1: Find Your HTS Code

Every product imported into the U.S. must be classified under the Harmonized Tariff Schedule (HTS). This 8–10 digit code determines your duty rate. Getting it right is critical — the wrong code can mean overpaying by thousands or underpaying and facing CBP penalties.

Three ways to find your HTS code:

  1. USITC HTS Search — search hts.usitc.gov by keyword. This is the official source but can be difficult to navigate.
  2. Ask your customs broker — a licensed broker can classify your products professionally.
  3. Use AI classification — tools like LandedCost use AI to determine the correct HTS code from a plain-English product description.

Step 2: Look Up Your Base Duty Rate

Once you have your HTS code, look up the General (MFN) duty rate in the tariff schedule. This is the baseline rate that applies to imports from most countries. Rates vary widely:

Product CategoryExample HTSMFN Rate
Bluetooth speakers8518.403.9%
Cotton t-shirts6109.1016.5%
Stainless steel water bottles7323.932%
Plastic phone cases3926.905.3%
Yoga mats (rubber)4016.992.5%

Step 3: Stack the Tariff Layers

The MFN rate is just the starting point. Depending on your product’s country of origin, additional tariff layers may apply:

Section 301 Tariffs (China)

Most goods from China face an additional 25% tariff under Section 301. Some product categories (like certain electronics) have different rates. These tariffs have been in effect since 2018 and show no signs of being removed.

Section 232 Tariffs (Steel and Aluminum)

Steel products face a 25% tariff and aluminum products face a 10% tariff under Section 232, regardless of country of origin (with some exceptions for USMCA partners).

IEEPA Tariffs

The International Emergency Economic Powers Act has been used to impose additional tariffs on specific countries. These can change with executive orders, making it essential to check current rates before shipping.

How Stacking Works

Example: Plastic phone case from China
MFN rate: 5.3% + Section 301: 25% = 30.3% effective duty rate

Step 4: Add MPF and HMF

On top of duties, every formal entry (over $2,500) is charged:

These are not duties — they are CBP processing fees that apply even to duty-free products. See our complete guide to MPF and HMF for details.

Step 5: Factor Into Your Product Pricing

Your actual cost per unit is the landed cost, not the supplier price. Here is a formula for eCommerce pricing:

Minimum selling price = Landed cost per unit + domestic shipping + platform fees + desired profit margin

For Amazon FBA sellers, platform fees include referral fees (8–15%), FBA fulfillment fees, and storage fees. For Shopify sellers, factor in payment processing (2.9% + 30¢) and shipping costs.

USMCA and Free Trade Agreements

If your products originate in Canada or Mexico, they may qualify for duty-free treatment under the United States-Mexico-Canada Agreement (USMCA), provided they meet the rules of origin requirements. Other FTAs exist with countries like South Korea, Australia, Colombia, and Israel. However, you must verify that your specific product qualifies — origin rules vary by product category.

The De Minimis Threshold ($800)

Under Section 321, shipments valued at $800 or less per person per day can enter the U.S. duty-free without formal entry. This is commonly used for direct-to-consumer shipments from overseas (e.g., AliExpress orders). However, the de minimis threshold does not apply to goods subject to anti-dumping or countervailing duties, and there are ongoing legislative efforts to lower or eliminate this threshold for imports from certain countries.

Common Mistakes eCommerce Sellers Make

  1. Using the supplier’s HS code — Suppliers often provide incorrect or outdated codes. Always verify independently.
  2. Ignoring tariff layers — The MFN rate is not the full story for Chinese imports. Section 301 alone adds 25% to most products.
  3. Forgetting MPF/HMF — These fees apply to every shipment, even duty-free ones.
  4. Not updating rates — Tariff rates change with policy. IEEPA and Section 301 rates have changed multiple times since 2024.
  5. Pricing on supplier cost alone — Your margin calculation must start from the full landed cost, not the FOB price.

Automate Your Duty Calculations

Manually looking up HS codes, checking tariff layers, and adding fees for every product is time-consuming and error-prone. The LandedCost calculator handles the entire process: enter your product description and country of origin, and get an instant breakdown of every cost component — including all tariff layers, MPF, and HMF.

Calculate Your Import Duties Free

Frequently Asked Questions

Do Amazon FBA sellers have to pay import duties?

Yes. If you import products from outside the U.S. to sell on Amazon FBA, you are the importer of record and are responsible for all customs duties, MPF, and HMF.

How do I find the HS code for my product?

You can search the USITC Harmonized Tariff Schedule database, ask your customs broker, or use an AI-powered classification tool like LandedCost that determines the HS code from a product description.

What is the de minimis threshold for imports?

The Section 321 de minimis threshold is $800 per shipment per person per day. Shipments under this value generally enter duty-free and without formal entry requirements.

How do tariff layers stack on Chinese imports?

Chinese imports can face the MFN base duty rate plus Section 301 tariffs (up to 25%), Section 232 tariffs on steel and aluminum, and IEEPA tariffs. These stack additively, so a product with a 5% MFN rate could face 30%+ effective duty.