How to Calculate Customs Tariff Duty

What is Customs Tariff Duty?

The Customs Tariff Duty Calculator determines the exact import duty owed on goods entering a country by looking up the Harmonized Tariff Schedule (HTS) code and applying the corresponding ad valorem, specific, or compound duty rate to the declared customs value.

Formula

Duty = Customs Value × Ad Valorem Rate (%) + Specific Duty per Unit × Quantity

CV: Customs Value ($) — Declared transaction value of imported goods including adjustments
R: Ad Valorem Rate (%) — Percentage duty rate from the HTS schedule
S: Specific Rate ($/unit) — Fixed duty amount charged per unit of measure
Q: Quantity (units) — Number of units imported in the applicable unit of measure

Step-by-Step Guide

1Classify your product using the correct 8-10 digit HTS code
2Look up the applicable duty rate (general, special, or column 2) for the HTS code
3Calculate the customs value (transaction value + assists + packing costs)
4Multiply the customs value by the ad valorem percentage and add any per-unit specific duties

Worked Examples

Input

HTS 6110.20 cotton sweaters, customs value $10,000, rate 16.5%

Result

Duty = $10,000 × 0.165 = $1,650

Input

HTS 2204.21 wine, 100 cases, $15,000 value, 6.3¢/liter + 0%

Result

Duty = 900 liters × $0.063 = $56.70

Common Mistakes to Avoid

✕Using the wrong HTS code, which can change the duty rate dramatically
✕Forgetting to include freight and insurance in the customs value for CIF countries
✕Not checking whether a preferential rate applies under a free trade agreement

Frequently Asked Questions

What is the difference between ad valorem and specific duty?

Ad valorem duty is a percentage of the goods value (e.g., 5%), while specific duty is a fixed amount per unit (e.g., $0.50 per kilogram). Some goods have compound duties combining both.

How do I find the correct HTS code for my product?

Use the USITC HTS search tool at hts.usitc.gov, consult a licensed customs broker, or request a binding ruling from CBP for certainty.

Does customs duty apply to samples or gifts?

Generally yes, unless the shipment qualifies under the de minimis threshold ($800 in the US) or falls under a specific exemption for bona fide samples of negligible value.

Ready to calculate? Try the free Customs Tariff Duty Calculator

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