How we calculate — and what we never do

Where the numbers come from

Every rate on this site is taken from official U.S. sources: the Harmonized Tariff Schedule as published by the U.S. International Trade Commission (this build: HTS 2026HTSRev22, 29,861 lines, 25,639 with rates), Chapter 99 additional-duty rules as published by USTR, the Federal Register and CBP (244 rules tracked), anti-dumping and countervailing duty orders from the U.S. Department of Commerce (890 cases), and the UFLPA Entity List from DHS (190 companies currently listed). Page built 2026-11-06.

How a total is built

A code's duty is layers, and we add them the way CBP's own rules say: the regular (MFN) rate first, then each Chapter 99 heading that covers the code and the origin — Section 301 lists, Section 232 programs, the 2026 forced-labor surtax — each under its own rule. One written exception matters: when a Section 232 tariff covers a product, U.S. note 52(f) says the forced-labor surtax does not stack on top, and we follow that. Country-specific combined-rate and threshold headings are never guessed: if the data cannot pin a heading to your origin, it is listed under "still to check" instead of being folded into the total.

What is never in a total

• Anti-dumping / countervailing duties. They depend on the written scope of an order and the specific producer. We flag possible cases on the code page; we never add them to a rate.
• UFLPA. It is a border-enforcement presumption, not a tax. It lives in its own list module, never in the calculator.
• Special program rates (free-trade agreements and the like) are shown for reference and only enter a calculation when eligibility is established — never assumed.

Fees

The Merchandise Processing Fee uses the fiscal-year parameters in 19 CFR 24.23, including the minimum and maximum per entry; the Harbor Maintenance Fee (19 CFR 24.24) appears only for ocean shipments. Entry date matters: rules are applied as of the date you give.

Limits

This site gives estimates from public data to help you plan and ask better questions. It is not a customs ruling, not brokerage, and not legal advice. Classification and final duty are decided by CBP on the actual goods.