MFN tariffs vs. additional tariffs

The number this calculator shows is the general, or "Most Favored Nation" (MFN), rate — the standard U.S. duty rate that applies to a product regardless of where it's made, published in the official Harmonized Tariff Schedule. For a lot of everyday imports, that's the whole answer. For others, it's only the floor — several separate programs can add to it, or occasionally replace it with something lower.

Section 301 and Section 232 tariffs

These are additional, product- and country-specific tariffs layered on top of the general rate — most visibly on a range of goods from China (Section 301) and on certain steel, aluminum, and related products regardless of origin (Section 232). They're assigned by product and origin, change with policy, and aren't part of the general schedule this calculator reads — so a product from an affected category can owe meaningfully more than the number shown here.

Free trade agreement (FTA) preferential rates

If the country of origin has a free trade agreement with the U.S. (like USMCA), a qualifying product can get a lower — often 0% — rate instead of the general one. Qualifying isn't automatic: it depends on rules of origin (how much of the product's value or processing actually happened in that country), and claiming it usually requires supporting documentation.

Antidumping and countervailing duties

These apply to specific products from specific countries that the U.S. has determined are being sold at unfairly low prices (antidumping) or are subsidized by their government (countervailing). Where they apply, the rates can be very large — sometimes well over 100% — and are set per case, not published as part of the general tariff schedule.

Why this calculator doesn't try to model these

Each of the categories above depends on country-of-origin and product-specific program codes that change independently of the general schedule. Mapping them incorrectly would produce a confident-looking number that's wrong — worse than being upfront that they aren't included. If your product or origin country could plausibly fall into any of these categories, treat the calculator's result as a floor, and check the official HTS or a customs broker before relying on a number for a real shipment.

Ready to check the general rate for your product? Head back to the tariff calculator.