How to calculate import duty

1. Establish the customs value

The default basis is transaction value: the price actually paid or payable for the goods when sold for export to the United States. Add packing costs, selling commissions, assists, royalties and proceeds of resale where they apply. International freight and insurance are not part of the dutiable value on a normal US entry, even when your invoice quotes a CIF price — the broker deducts them.

2. Choose the rate column

Use the general (Column 1) rate unless the goods qualify under a trade agreement, in which case the special rate applies — but only if you can substantiate the rules of origin. Column 2 applies to Cuba, North Korea, Russia and Belarus.

3. Apply the rate

Ad valorem rates like 6.5% are a straight percentage of the customs value. Specific rates like 6.8¢/kg are charged on quantity, so you need the weight or piece count in the unit the code specifies. Compound rates are both added together.

4. Add the standard fees

The merchandise processing fee is charged ad valorem on formal entries, subject to a published minimum and maximum per entry. The harbor maintenance fee applies to ocean shipments arriving at US ports. Both are set by CBP and change periodically, so confirm current rates with your broker.

5. Add trade-remedy tariffs

These are where estimates most often go wrong. Section 301 duties on Chinese-origin goods, Section 232 duties on steel and aluminium, and antidumping or countervailing duty orders are all applied on top of the normal rate and are keyed to specific HTS codes. They can exceed the base rate several times over.

Try it with your own numbers