How to Calculate Tariffs

It is strongly recommended to engage a licensed customs broker or professional tariff consultant when calculating import duties. The process can be complex, with a high potential for errors, fines, and penalties if classifications are inaccurate. While online calculators can provide rough estimates, a qualified professional ensures proper identification of the Harmonized System (HS) code, application of relevant trade agreements, and completion of all required documentation—helping to prevent costly mistakes and delays. The information below is provided for reference purposes only.

Tariffs are taxes imposed by governments on imported goods. They serve as trade barriers that make foreign products more expensive and can be used to protect domestic industries, generate government revenue, or advance foreign policy objectives. The cost is typically borne by importers and often passed on to consumers through higher prices.

Tariff calculation as of November 2025 involves a complex and shifting landscape of various tariffs on goods, including a 10% universal tariff, country-specific rates (e.g., 25% on non-USMCA goods from Mexico, 30% on goods from China), and specific tariffs on products like steel, aluminum, copper, automobiles and parts and trucks. To calculate the specific tariff for a product, you must first correctly identify its Harmonized Tariff Schedule (HTS) code, then determine if it’s subject to a general, country-specific, or product-specific tariff, and finally apply the correct rate to the product’s customs value.

Key Tariff Rates and Policies as of November 2025

1. Universal Tariff: A 10% “Liberation Day” tariff is in effect for most imports.

2. Country-Specific Tariffs:

• • China: An additional 20% tariff is in effect, bringing the total tariff on most goods to 30% (10% universal + 20% specific) until November 10, 2025. Further changes to Chinese imports are expected.
  • Mexico: A 25% tariff on non-USMCA compliant goods.
  • Canada: A 35% tariff on non-USMCA compliant goods.
  • European Union & Japan: A minimum 15% tariff if the standard rate was lower, with specific rates varying by product.

3. Product-Specific Tariffs:

• • Steel and Aluminum: A 50% global ad valorem tariff has been implemented, with the exception of the United Kingdom, which remains at 25%.
  • Copper: As of November 2025, a 50% ad valorem tariff is applied to U.S. imports of semi-finished copper products and derivative products, such as wire, tubing, and fittings, effective August 1, 2025. *
    *The tariff calculation is based on the value of the steel, aluminum and/or copper component of the product.
  • Automobiles and Parts: A 25% global tariff is in effect.
  • Trucks and Parts: A new 25% tariff on medium- and heavy-duty trucks and key parts went into effect on November 1, 2025.

How to Calculate a Specific Tariff

1. Identify the correct Harmonized Tariff Schedule (HTS) code for your product. This is the most critical step.

2. Determine the country of origin: The country where the goods were manufactured is essential for applying country-specific tariffs.

3. Check for product-specific tariffs: See if the product falls under any specific categories, like steel, aluminum, or trucks, that have separate, higher tariffs.*

4. Add the universal tariff: Begin your calculation with the 10% universal tariff.

5. Add country-specific or product-specific tariffs: Add the applicable country-specific rate or product-specific rate to the universal tariff. For example, a non-USMCA compliant good from Mexico would have a base of 10% universal + 25% specific = 35% tariff.

You can find current US country-specific and product-specific tariffs on official government sites like the USITC Tariff Database.

While some tariffs apply cumulatively, called “stacking”, others are mutually exclusive. To learn more about which tariffs follow hierarchy rules versus those that accumulate, please visit https://globaltradealert.org/blog/US-Tariff-Stacking-Explained.

6. Apply the rate to the customs value: The US uses the transactional value** of imported merchandise for customs duty purposes. Multiply the customs value of the imported good by the total percentage to find the final tariff amount. For example, a $100,000 shipment of non-USMCA compliant goods from Mexico would be subject to a $35,000 tariff ($100,000 x 0.35).

**For U.S. Customs, transaction value is the primary method for determining the value of imported goods. It is based on the price actually paid or payable for the merchandise when it is sold for export to the United State. The value must include additional costs like packing costs, selling commissions, royalties, and licenses fees.

Components of Transactional Value

1. Price: The total price paid or to be paid by the buyer to the seller.

2. Additions: The following costs are added to the price, if not already included:

• • Packing costs: All costs for packing, including containers, coverings, and labor.
  • Selling commission: Any selling commission paid by the buyer.
  • Assist: The value of any “assist,” which is a service or item provided by the buyer to the seller for free or at a reduced cost to produce the imported goods.
  • Royalty or license fee: Any royalty or license fee the buyer must pay as a condition of the sale.
  • Proceeds: The value of any proceeds from the subsequent resale, disposal, or use of the goods that the seller receives, directly or indirectly.

For purposes of calculating the steel, aluminum, and now copper content of products subject to Section 232 tariffs, it is essential to conduct a detailed analysis of the Bill of Materials (BOM). A component-by-component review must be performed to determine whether each component contains any of these metals. For components that do contain steel, aluminum, or copper, detailed information must be obtained regarding their value, weight, and—specifically for steel and aluminum—where the material was poured, cast, or molded. This requirement applies regardless of the component’s tariff classification.

Accurate information must be obtained directly from suppliers to ensure compliance; estimates or second-hand data are not acceptable. U.S. Customs and Border Protection (CBP) has increased the frequency and depth of its audits for these entries. Errors or irregularities may result in significant fines and penalties, in addition to the obligation to pay Section 232 tariffs on the full value of the product. If the country of origin of the metal is unknown, the tariff rate may be as high as 200%.