Visualize how multiple U.S. tariff layers — base MFN duty, Section 301, Section 232, and Section 122 — compound on a single import shipment. Enter your product value and toggle each tariff section to see the stacking effect.
See how multiple tariff layers compound on a single import shipment. Toggle each section on or off to visualize the stacking effect on your landed cost.
Enter the base MFN duty rate for your HTS code. Ranges from 0% (most electronics) to 37.5%+ (apparel, textiles).
At 5.0% effective rate, your duty exposure is within a typical range. Ensure your HTS classification is accurate to avoid overpayment.
The Most-Favored-Nation rate is the baseline U.S. import duty determined by your product's HTS code. Every country gets this rate unless an FTA (like USMCA) provides a zero or reduced rate. Rates range from 0% on electronics to over 30% on apparel and textiles.
Authorized under Section 301 of the Trade Act of 1974, these tariffs apply only to goods manufactured in China. Lists 1–3 (industrial goods) carry 25%. List 4A (consumer goods) carries 7.5%. List 4B was suspended. These stack on top of the base MFN rate.
National security tariffs under the Trade Expansion Act of 1962. As of March 2025, steel and aluminum imports face a 50% tariff from all countries with no exemptions. Canada and Mexico are NOT exempt despite USMCA. This is one of the highest individual tariff layers.
A 10% universal import surcharge effective February 24, 2026 under Section 122 of the Trade Act of 1974. This replaced the IEEPA reciprocal tariffs after the Supreme Court ruling. Canada and Mexico are exempt under USMCA. All other countries pay this on top of other layers.
U.S. import tariffs are additive, not multiplicative. Each tariff layer is calculated as a percentage of the original declared customs value. For a $10,000 shipment of steel from China:
That's why understanding tariff stacking is critical — a single product can face an effective duty rate of 85%+ when all layers apply. Use our Duty & Tariff Calculator for product-specific rates, or read our Tariff Stacking Guide for strategies to reduce exposure.
Common questions about tariff stacking and compound duty rates
Tariff stacking refers to the cumulative effect of multiple tariff layers applied to a single import shipment. For example, steel imported from China can face a base MFN duty, plus Section 301 tariffs (25%), plus Section 232 tariffs (50%), plus Section 122 (10%) — all stacking on the same customs value. The effective combined rate can exceed 85%.
U.S. tariff layers are additive, not multiplicative. Each layer is calculated as a percentage of the declared customs value. So a $10,000 shipment with 5% MFN + 25% Section 301 + 10% Section 122 = 40% effective rate = $4,000 total duty. All layers apply to the original product value, not compounded on top of previous layers.
As of March 2026, Chinese imports may face up to four tariff layers: base MFN duty (varies by HTS code), Section 301 tariffs (25% for Lists 1–3, 7.5% for List 4A), Section 232 tariffs (50% on steel and aluminum), and Section 122 universal tariff (10%). For steel from China, the combined rate can exceed 85%.
All U.S. tariff layers are calculated on the original declared customs value (ad valorem), not compounded. A $10,000 item with 5% MFN and 25% Section 301 pays $500 + $2,500 = $3,000, not $500 + $2,625 (which would be the compounded amount). You can simply sum the percentages to get the effective rate.
Strategies include: sourcing from FTA partner countries (USMCA eliminates MFN and §122 for Canada/Mexico), using Foreign Trade Zones (FTZs) for duty deferral, bonded warehouse storage, first-sale valuation to lower customs value, and reviewing HTS classification to ensure accurate duty rates. A licensed customs broker can advise on the best strategy.
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