How to Calculate Customs Duty When Importing from China: A 2026 Guide

TL;DR – Key Takeaways for Importers

• Start with the right HTS code: U.S. HTS codes differ from Chinese HS codes beyond the first 6 digits. Use the USITC HTS database to find the correct 10-digit code for your product before calculating duty.

• The 2026 tariff stack is layered: Base MFN duty + old Section 301 tariffs (7.5–25%) + new Section 301 forced-labor tariffs (12.5%, effective July 24, 2026) + Section 232 tariffs for steel/aluminum/copper (25–50%).

• De minimis is suspended: Shipments valued under $800 now face a flat fee structure – $80–$200 per postal package depending on tariff tier, plus potential ad valorem duties.

• 301 exemptions exist but have deadlines: Certain product categories are exempt from Section 301 tariffs through November 29, 2026. Check the exemption list before calculating.

• Customs value is not the supplier's invoice: For U.S. imports, customs value must include freight, insurance, packing costs, and certain assists or royalties.

Introduction: Why Calculating Customs Duty Matters

When you import goods from China to the United States, the price you pay your supplier is only the beginning. Once your goods arrive at the U.S. port, Customs and Border Protection (CBP) will assess duties based on the product's classification, declared value, and a growing stack of tariffs layered onto Chinese imports.

In 2026, the tariff landscape for Chinese imports is more complex than ever. A new 12.5% Section 301 "forced-labor" tariff took effect on July 24, 2026, stacking on top of existing 7.5–25% Section 301 tariffs. Meanwhile, the suspension of the de minimis exemption on August 29, 2025, means that even small parcels now incur duties.

This guide provides a practical framework for calculating customs duty when importing from China to the United States. It covers the formula, the key inputs, and the 2026 tariff landscape that every importer must navigate.

Step 1: Find the Correct U.S. HTS Code

The first step in calculating duty is identifying the correct 10-digit Harmonized Tariff Schedule (HTS) code for your product. The U.S. uses HTS codes that differ from Chinese HS codes beyond the first 6 digits.

How HTS Codes Work

HTS codes are 10-digit numbers that classify imported products. The first 6 digits are internationally standardized (HS codes), while the last 4 digits are specific to the United States.

Key Resources for HTS Lookup

Pro Tip: Always verify your HTS code classification with a customs broker before importing. Misclassification can result in penalties and delayed shipments.

Step 2: Determine the Base MFN Duty Rate

Once you have the correct HTS code, the first duty rate you will see is the Most Favored Nation (MFN) rate – the standard duty applied to imports from WTO member countries, including China.

Duty rates can be:

• Ad Valorem: Percentage of product value (e.g., 3.2% means 3.2% of declared value)

• Specific Duty: Fixed amount per unit (e.g., $0.32/kg)

• Combination: Both ad valorem and specific

Example: For HTS code 8465.92.00 (woodworking machines), the MFN duty rate is approximately 3.2%.

Step 3: Apply Section 301 Tariffs

Since 2018, the U.S. has imposed additional tariffs on Chinese goods under Section 301. In 2026, these tariffs are layered as follows:

Important: The new 12.5% "forced-labor" tariff is additive to the old Section 301 tariffs. If your product is subject to a 25% old Section 301 tariff, the combined additional tariff is 37.5% – plus the base MFN duty.

Example – Power Adapter (HTS 8504.40.85) :

• Base MFN duty: ~2.5%

• Old Section 301 (List 3): 25%

• New Section 301 (Forced Labor): 12.5%

• Total duty rate: 40%

Step 4: Check for Section 232 and Other Tariffs

Certain product categories face additional duties outside the Section 301 framework:

The 12.5% forced-labor duty does not stack with Section 232 tariffs.

Step 5: Check for 301 Exemptions

Certain product categories are exempt from Section 301 tariffs through November 29, 2026. If your product falls under an exemption, you do not need to pay the 301 tariff layer – only the base MFN duty.

Exempted categories include:

• Certain electronics and components

• Medical supplies and equipment

• Specific industrial machinery

• Solar manufacturing equipment

Tip: Always check the current USTR exemption list before calculating duty.

Step 6: Calculate the Customs Value

The customs value (also called "transaction value") is not simply your supplier's invoice. Under U.S. law (19 U.S.C. § 1401a), it includes:

Common Undervaluation Schemes to Avoid :

• Falsified invoices: Listing values lower than the actual transaction price

• Double invoicing: One true invoice, one reduced invoice for customs

• Omitting required statutory additions: Excluding packing costs or assists

Risks of Undervaluation: Customs fraud can expose importers to back duties, civil penalties, loss of trusted trader status, and even criminal prosecution. The DOJ has identified customs fraud as a top enforcement priority.

Step 7: Factor in De Minimis and Postal Shipments

Since August 29, 2025, the $800 de minimis exemption has been suspended for all countries.

For postal shipments, flat fees apply based on the country's tariff tier:

• Under 16% tariffs: $80 per postal item

• 16–25% tariffs: $160 per postal item

• Over 25% tariffs: $200 per postal item

For commercial shipments: All applicable tariffs, including Section 301 duties, apply regardless of value.

Step 8: Calculate the Total Duty

Final Formula:

Total Duty = Customs Value × (MFN Rate + Applicable Section 301 Tariffs + Section 232 if applicable)

Complete Example: A power adapter (HTS 8504.40.85) with CIF value of $10,000:

• Customs value: $10,000 (including freight and insurance)

• MFN duty: $10,000 × 2.5% = $250

• Old Section 301: $10,000 × 25% = $2,500

• New Section 301: $10,000 × 12.5% = $1,250

• Total Duty: $4,000 (40% effective rate)

Common Mistakes and How to Avoid Them

Mistake 1: Using Chinese HS Code Instead of U.S. HTS Code

The first 6 digits match, but the full 10-digit code differs. Fix: Always verify the complete 10-digit U.S. HTS code.

Mistake 2: Declaring Only Supplier Invoice Value

U.S. customs value must include freight, insurance, packing costs, and assists. Fix: Include all required additions.

Mistake 3: Ignoring New 301 Tariffs

The 12.5% forced-labor tariff took effect July 24, 2026. Fix: Update duty calculations to include both old and new 301 tariffs.

Mistake 4: Forgetting Section 232 for Steel/Aluminum

Products containing steel or aluminum may face 25% Section 232 duties. Fix: Check if your product is subject to Section 232.

Mistake 5: Assuming De Minimis Still Applies

The $800 de minimis exemption was suspended on August 29, 2025. Fix: Budget for duties on all shipments.

Step-by-Step Guide: Duty Calculation Workflow

Step 1: Identify Your Product

• Describe your product accurately (material, function, specification)

• Gather supplier specifications, material composition, and intended use

Step 2: Look Up HTS Code

• Search the USITC HTS database by product description or the first 6 digits of the Chinese HS code.

• Verify the 10-digit code is correct for your product

Step 3: Determine Base MFN Rate

• Note the Column 1 (Normal) duty rate for your HTS code

Step 4: Check Section 301 Tariffs

• Confirm if your product is subject to old Section 301 tariffs (7.5–25%)

• Confirm if your product is subject tothe  new 12.5% forced-labor tariff (China origin)

• Check for any 301 exemptions

Step 5: Check Section 232 (if applicable)

• For steel, aluminum, copper, or automotive products, confirm 25–50% Section 232 duties.

Step 6: Calculate Customs Value

• Include price paid + packing + assists + freight + insurance

• Verify with your supplier and forwarder

Step 7: Apply the Formula

• Total Duty = Customs Value × (MFN + Section 301 + Section 232)

Frequently Asked Questions (FAQ)

Q1: What is the difference between a Chinese HS code and a U.S. HTS code?

A: The first 6 digits are the same globally. Beyond that, the U.S. uses a 10-digit HTS code, while China uses an 8- to 10-digit HS code. Always use the U.S. HTS code for U.S. duty calculations.

Q2: What is the Section 301 tariff rate on Chinese goods in 2026?

A: Rates range from 7.5% to 25% for old Section 301 tariffs, with an additional 12.5% "forced-labor" Section 301 tariff effective July 24, 2026. The combined rate depends on your product classification.

Q3: Are any Chinese goods exempt from Section 301 tariffs?

A: Yes. Certain product categories are exempt through November 29, 2026. Check the current exemption list before calculating.

Q4: How is customs value determined for U.S. imports?

A: Customs value includes the transaction value (price paid) plus packing costs, selling commissions, assists (materials/tools provided by buyer), royalties, and freight/insurance.

Q5: What is the duty rate for shipments under $800?

A: Since August 29, 2025, the de minimis exemption is suspended. Postal shipments are subject to flat fees ($80–200 per package). Commercial shipments pay all applicable tariffs.

Q6: What is the risk of undervaluation?

A: Customs fraud can lead to back duties, civil penalties, loss of trusted trader status, and criminal prosecution. The DOJ has identified customs fraud as a top enforcement priority.

Q7: Is there an Incoterms 2026 update?

A: No. Incoterms 2020 remains the current official version. The next revision is expected around 2030.

Conclusion: Accuracy Saves Money

Calculating customs duty when importing from China to the U.S. requires attention to multiple layers: the base MFN rate, old Section 301 tariffs, new 12.5% forced-labor tariffs, potential Section 232 duties, and accurate customs value determination.

The most important advice for importers: verify your HTS code, check for exemptions, and declare accurate values. A small mistake in classification or valuation can lead to significant overpayment – or a customs audit with serious legal consequences.