General duty
The HTSUS general rate starts the calculation
The selected HTSUS line may be Free, ad valorem, specific, compound or conditional. The ordinary duty is one component and can be zero even when other charges apply.
Additional tariffs
Chapter 99 measures can add a separate duty
Origin- and product-specific measures can refer to Chapter 99 headings. TariffCalc automatically applies only its deterministic, source-backed Section 301 registry and the locked China-origin primary-steel Section 232 family implemented in Phase 25. Unsupported measures remain review required or outside coverage.
MPF
Formal-entry Merchandise Processing Fee uses a rate with minimum and maximum
For the bundled FY2026 formal-entry rule, TariffCalc uses 0.3464 percent of customs value, subject to a $33.58 minimum and $651.50 maximum. Exemptions, informal entries and special entry types are not inferred.
HMF
Harbor Maintenance Fee depends on covered vessel and port use
The regulation applies a 0.125 percent fee to specified commercial cargo loaded or unloaded from a commercial vessel at a covered port, subject to exemptions and special rules. TariffCalc adds it only after ocean transport and covered applicability are explicitly confirmed.
Outside the estimate
Review charges the calculator does not automate
AD/CVD, Section 232 outside the locked implemented primary-steel family, Section 122, safeguards, quotas, excise, preference eligibility, product exclusions, broker fees, carrier charges, storage and local delivery can require separate analysis.
Questions
Frequently asked questions
Does a Free HTS rate mean no US import fees?
No. Additional tariffs, MPF, HMF or other measures can still apply even when the ordinary general duty rate is Free.
Are MPF and HMF the same fee?
No. Formal-entry MPF is a merchandise processing user fee with a rate, minimum and maximum. HMF is a separate port-use fee for covered commercial-vessel cargo.
Does TariffCalc include broker or carrier charges?
No. User-entered shipping and insurance are shown separately, while broker, carrier, storage and local delivery charges remain outside automatic tariff coverage.