How US import duty is calculated
Duty = Entered value × (Base HTS rate + Section 301 + Section 232 × share covered + Other duties)
MPF = 0.3464% × Entered value, between $34.58 and $670.86 per formal entry (FY2027)
HMF = 0.125% × Entered value (ocean shipments only)
Landed cost = Entered value + Freight + Insurance + Duty + MPF + HMF + Broker + Bond + Other costs
The United States charges duty on the transaction value of the goods - what you paid the seller - rather than on a CIF value that includes shipping, as the UK and EU do. Each duty is a percentage of that same value, so when several apply they simply add up. A product with a 3.9% base rate and a 25% Section 301 duty pays 28.9% on its value before any fees.
Entries valued above $2,500 are generally formal entries, which pay the percentage MPF within its minimum and maximum. At or below $2,500 an informal entry pays a small flat fee, although goods subject to additional duties or antidumping orders often have to be filed as formal entries at any value.
Worked example
An Amazon seller imports 2,000 units valued at $6.50 each by ocean. The product’s HTS line has a 3.9% general rate and is also subject to a 25% Section 301 duty. These rates are illustrative, not the rates for any particular product.
| Entered value | 2,000 × $6.50 = $13,000.00 |
| Base duty at 3.9% | $507.00 |
| Section 301 at 25% | $3,250.00 |
| MPF at 0.3464% | $45.03 (between the $34.58 minimum and $670.86 maximum) |
| HMF at 0.125% | $16.25 |
| Total paid to CBP | $3,818.28, or 29.37% of the value |
| Freight, insurance, broker, bond and drayage | $1,400 + $40 + $125 + $75 + $350 |
| Landed cost | $18,808.28, or $9.40 per unit |
The product costs $6.50 at the factory but $9.40 once it is in the US. The Section 301 duty alone adds $1.63 per unit - money that has to come out of margin or be passed on in the price. Use the landed cost in the Amazon FBA or Shopify margin calculator to check the product still pays.
The tariff layers to check in 2026
US tariff policy has changed several times since 2025. When you price an import, check each of these layers for your HTS code and country of origin:
- Base duty (HTS Column 1). The general rate for the 10-digit code, or a lower special rate if the goods qualify under a trade agreement such as USMCA.
- Section 301 duties. The long-standing duties on many goods from China, from 7.5% to 25% and higher for some products after the 2024 review, plus the country-specific Section 301 tariffs that took effect on July 24, 2026, reported at around 10% to 12.5% for about 60 countries.
- Section 232 duties on national-security grounds, covering steel, aluminum and copper and their derivatives, vehicles and parts, and other product groups. Some apply only to the metal content of a product.
- Antidumping and countervailing duties (AD/CVD) on specific products from specific producers or countries.
- What no longer applies: the IEEPA tariffs, struck down by the Supreme Court on February 20, 2026, and the temporary 10% Section 122 surcharge that replaced them, which expired on July 24, 2026.
Rates change at short notice. This page was last checked on October 27, 2026. Confirm every rate in the HTS and CBP’s Cargo Systems Messaging Service before you rely on an estimate, and use a licensed customs broker for binding advice.
Ways to lower the duty you pay
- Classify correctly. A different but accurate 10-digit HTS code can carry a very different rate. Ask for a binding ruling if in doubt.
- Check the country of origin. Origin follows where the goods are substantially transformed, not where they ship from.
- Use trade agreements. Goods that qualify under USMCA or another agreement can pay a lower rate and, often, no MPF.
- Consolidate shipments. MPF has a per-entry minimum and maximum, so fewer, larger entries spread it further.
- Look at duty drawback and foreign-trade zones if you re-export goods or hold stock for a long time before it enters US commerce.
Methodology and sources
Amounts are calculated in whole cents. Each line is rounded once, half away from zero, and totals are exact sums of the rounded lines. MPF and HMF use CBP’s fiscal year 2027 amounts (CBP Dec. 26-14, effective October 1, 2026). No tariff rates are built in: you enter the rates that apply to your goods.
- Harmonized Tariff Schedule of the United States, US International Trade Commission (hts.usitc.gov).
- U.S. Customs and Border Protection, user fees and trade guidance (cbp.gov/trade).
- Office of the United States Trade Representative, Section 301 actions (ustr.gov).
Frequently asked questions
How is US import duty calculated?
US duty is a percentage of the entered value of the goods, which is normally the price paid to the seller without international freight and insurance. You add the base rate from the Harmonized Tariff Schedule (HTS) for the product’s 10-digit code to any additional duties that apply, such as Section 301 or Section 232 duties, then add the merchandise processing fee and, for ocean freight, the harbor maintenance fee.
Is international shipping included in the dutiable value?
Generally no. The United States values most imports on the transaction value, and international freight and insurance are excluded when they are shown separately. That is why this calculator charges duty on the goods value only, while still adding freight and insurance to your landed cost.
What are MPF and HMF?
The merchandise processing fee (MPF) is 0.3464% of the entered value on a formal entry, with a minimum of $34.58 and a maximum of $670.86 per entry for fiscal year 2027 (from October 1, 2026). Informal entries pay a small flat fee instead. The harbor maintenance fee (HMF) is 0.125% of the value of cargo arriving by ocean.
Is there still an $800 duty-free de minimis limit?
No. The $800 de minimis exemption has been suspended, so low-value commercial shipments are subject to duty, and in June 2026 CBP also suspended it indefinitely for international mail. Budget duty on every shipment, whatever its value.
What happened to the IEEPA tariffs?
On February 20, 2026 the Supreme Court held that the International Emergency Economic Powers Act does not authorize tariffs, so duties imposed under it stopped applying and CBP set up a refund process for importers who paid them. Other tariffs, including Section 301 and Section 232 duties, were not affected by that ruling.
Do stacked tariffs apply to the same value?
Usually each additional duty is a separate percentage of the same entered value, so the rates add up. Some Section 232 duties on derivative products apply only to the value of the metal content, and some combinations of duties do not stack. Check the Chapter 99 notes for your HTS code, or ask a licensed customs broker.