Step 1
Identify the complete US HTS classification
Start with the product’s materials, composition, function, condition and use. Select the applicable 10-digit HTSUS reporting line when possible and preserve the classification evidence and tariff-schedule version.
Step 2
Confirm country of origin and import date
Origin can affect Chapter 99 measures and trade-program eligibility. The import date determines which tariff schedule and fee rules are effective. TariffCalc blocks future dates because unpublished future rules should not be guessed.
Step 3
Determine the customs value
US customs valuation is governed by statutory methods and transaction-value rules, not merely by whatever number appears convenient on a commercial invoice. Assists, packing, proceeds, related-party conditions and other adjustments can matter.
Step 4
Calculate the ordinary or general duty
For a simple ad valorem general rate, multiply customs value by the published percentage. Free rates produce zero ordinary duty. Specific and compound rates require the quantity and matching unit. Conditional formulas require review when they cannot be modeled deterministically.
Step 5
Evaluate additional tariffs and fees separately
Review applicable Chapter 99 measures, including supported Section 301 or Section 232 rules, as separate components. Then evaluate formal-entry MPF and ocean HMF based on confirmed entry and transport facts. AD/CVD, quotas, safeguards, excise and preferences can require separate analysis.
TariffCalc’s automatic scope is intentionally narrower than all possible US import charges. Read every coverage warning.
Questions
Frequently asked questions
Is import duty calculated on shipping cost?
Not as a universal shortcut. Duty is calculated on the legally determined customs value and the applicable rate formula. TariffCalc shows separately entered shipping and insurance so users can avoid silently applying duty to the wrong base.
Does a Free general rate mean the import has no tariff cost?
No. A Free ordinary rate can still be accompanied by Chapter 99 additional duties, formal-entry MPF, HMF or other measures and fees.
Can an online estimate replace a customs ruling?
No. An estimate is decision support. Classification, valuation or measure uncertainty may require CBP guidance, a qualified professional or a binding ruling.