Customs Duty Calculator

US customs duty calculation starts with establishing the correct customs value under 19 CFR 152, then applying the duty rate for the classified HTS heading to that value. For most commercial imports, that's straightforward. For goods subject to multiple tariff measures — Section 301, Section 232, IEEPA reciprocal tariffs — the layers stack. A shipment of Chinese-origin aluminum extrusions might face 3% standard duty, 10% Section 232 aluminum, 25% Section 301 List 3, and IEEPA reciprocal tariffs simultaneously. We provide worked calculations for common product categories, explain how to read the HTSUS "special" column, and show where MPF and HMF fit into the final entry total.