US Import Duty Guide: How Tariffs Work and How to Calculate Your Cost

When you import goods into the US, you'll pay customs duties calculated on the declared value of your shipment. Get this wrong in your cost model and a profitable product can quickly turn into a money-loser. This guide explains how US import duties work, how to look up rates, and how to estimate your total duty cost.

How US Import Duties Are Calculated

US import duty is a percentage of the customs value of your goods — typically the transaction value (what you paid the supplier), not including international freight and insurance (unless the shipment is CIF-based).

Duty = Customs Value × Duty Rate (%)

The duty rate depends on two things:

1. The HS code — the tariff classification of your product
2. The country of origin — where the product was manufactured

Finding Your HS Code and Duty Rate

Every product has an HS code (Harmonized System code), a 10-digit number used by US customs to classify goods. The first 6 digits are the same globally; the last 4 are US-specific (HTS code).

To find your rate:

1. Look up your product in the USITC HTS database (hts.usitc.gov)
2. Find the Column 1 "General" rate — this applies to most-favored-nation (MFN) countries
3. Check if additional Section 301 tariffs apply (for Chinese-origin goods)
4. Check for duty-free treatment under trade agreements (USMCA for Canada/Mexico, KORUS for South Korea, etc.)

Common Duty Rates by Category

Rates as of 2026. Always verify current rates for your specific HTS code before importing.

The $800 De Minimis Threshold

Shipments with a customs value at or below $800 enter the US duty-free under the de minimis rule (Section 321). This is the rule that made direct-from-China platforms (like Shein and Temu) viable — they shipped individual orders under $800 duty-free.

Note: de minimis thresholds are being reduced for Chinese-origin goods as of 2025–2026. Check current CBP guidance if you're relying on de minimis for your business model, as this policy is changing.

Formal vs Informal Entry

• Informal entry: shipments valued below $2,500 can often be cleared without a licensed customs broker
• Formal entry: required for commercial shipments above $2,500. You need a customs broker (licensed by CBP) to file the entry. Broker fees typically range from $100–300 per entry.

Duty in Your Landed Cost Calculation

Duty is one component of landed cost. Total landed cost per unit:

Landed Cost = FOB Price + Freight + Insurance + Customs Duty + Customs Broker Fee + Last-Mile Delivery

For a product with $5 FOB, 25% Section 301 tariff + 5% base rate = 30% total duty:

• FOB: $5.00
• Freight (ocean, per unit): $0.80
• Duty: $5.00 × 30% = $1.50
• Broker fee (per unit, at 5,000 units): $0.05
• Landed cost: ~$7.35

A 30% duty rate turned a $5 product into $7.35 before it reaches your warehouse. Miss this in your cost model and you've priced yourself into a loss.

Frequently Asked Questions

How much is US import duty?

It varies by HS code and country of origin. Most goods face 0–25% standard MFN rates. Chinese goods have additional Section 301 tariffs of 7.5–25% depending on the product list.

Do I pay customs duty on goods from China?

Yes, for shipments above $800. Both standard MFN tariffs and Section 301 tariffs apply to Chinese-origin goods for most product categories.

What is an HS code?

A standardized 6–10 digit number classifying traded goods. Every product has one; it determines the duty rate. Look up yours at hts.usitc.gov.

What is the Section 301 tariff?

Additional US tariffs on Chinese-origin goods enacted from 2018. Rates range from 7.5% to 25% depending on the product and tariff list. They add on top of standard MFN duty rates.