How to Calculate US Import Duty (2026)

The formula

For a commercial entry the government lines are:

1. Customs value of the merchandise. For most arm's-length sales this is transaction value under 19 U.S.C. § 1401a: the price actually paid or payable, with the statutory additions and deductions.
2. Duty = customs value × the stacked ad valorem rate for the HTS classification and the country of origin. Specific and compound rates (dollars per kilogram, or a mix) are a different sum. This site's category calculator is ad valorem.
3. Merchandise Processing Fee, a CBP user fee under 19 U.S.C. § 58c. On a formal entry this site uses 0.3464% of value, with the FY2026 floor of $33.58 and ceiling of $651.50.
4. Harbor Maintenance Fee at 0.125% of value on ocean cargo, the rate in 26 U.S.C. § 4461. Air cargo does not pay it.
5. Brokerage and freight, which you type. They are not CBP duties.

The legal rate book is the Harmonized Tariff Schedule published by the USITC. This site stacks a curated snapshot of that schedule. It is not a binding classification and not the number on a CBP Form 7501.

Which layers actually add

Read the breakdown, not a single country headline.

• Column 1 (MFN) is the general rate on the HTS line. Apparel in this dataset often uses 16.5%. Many electronics lines are free.
• Section 301 forced-labor tariff replaced the expired Section 122 surcharge on July 24, 2026. In this calculator it is 10% or 12.5% by economy. China and Vietnam are in the 12.5% tier.
• China Section 301 is a separate list rate, 7.5% to 100% depending on the product. It does not apply to Vietnam, Mexico, or Germany.
• EU ordinary goods are a 10% net of Column 1 (U.S. note 52(k)). If Column 1 is already at least 10%, the additional duty is zero. Autos, qualifying semiconductor articles, and drones stay at 15% in lieu of Section 232.
• Section 232 on steel, aluminum, and copper is assessed on the metal and does not take the forced-labor layer on that metal content. A wholly-steel article in this calculator is 50%, not 60%. Chinese wholly-steel is 50% Section 232 plus 25% China Section 301, 75%, not 85%.
• USMCA can zero the stored category rate for qualifying Mexican or Canadian goods. It does not zero Section 232, and it does not zero a passenger vehicle in note 33(b).

The $800 Section 321 exemption is not in the formula. It is suspended. See the de minimis rule.

Fees: the part that is not the tariff

Formal entries, generally over $2,500, pay MPF of 0.3464%, at least $33.58 and at most $651.50 in the FY2026 figures this site publishes. The straight percentage applies only in the middle band. Below about $9,700 the floor binds. Above about $188,000 the ceiling binds ($651.50 ÷ 0.003464).

Informal entries at or under $2,500 pay a flat MPF. This calculator uses the low automated figure, $2.69, and says so. The other published informal amounts are $8.06 and $12.09, depending on how the entry is filed. Crossing $2,500 changes the fee structure, not just the duty.

Ocean HMF is 0.125% with no floor in this module. On $10,000 it is $12.50. On an air shipment it is $0.

The line order, and a different worked shipment, is the landed cost calculation structure. The fee rules are the merchandise processing fee guide.

Example: a $400 air shipment from China

Inputs typed into calculateLandedCost, China, electronics category, not ocean:

• Customs value: $400
• Duty: 37.5% = $150.00 (25% China Section 301 + 12.5% forced-labor; category MFN is 0%)
• MPF: $2.69 (informal, the low figure this module uses)
• HMF: $0 (air)
• Freight you type: $35
• Brokerage you type: $19.50 (the FedEx entry-preparation amount this site already quotes for the $200.01–$800 band; it is the carrier's fee, not CBP's)

Estimated total: $607.19. Duty is $150 of that. The rest is freight, the informal MPF, and the brokerage you typed. A different informal MPF tier ($8.06 or $12.09) changes only that one line.

Example: $2,500 of clothing from Vietnam

Vietnam clothing in this calculator is 29%: 16.5% base + 12.5% forced-labor. On a customs value of exactly $2,500 the module still treats the entry as informal.

• Duty: 29% × $2,500 = $725.00
• MPF: $2.69
• Ocean HMF: 0.125% × $2,500 = $3.13
• Freight you type: $420
• Insurance you type: $20
• Brokerage you type: $150

Estimated total: $3,820.82.

One dollar more, $2,501, is a formal entry in this module. Duty becomes about $725.29. MPF jumps from $2.69 to the $33.58 floor, because 0.3464% of $2,501 is under that floor. The threshold is why a shipment split across the $2,500 line can cost more in fees than it saves in anything else.

Example: $10,000 and $80,000 of Chinese electronics

Same category, China electronics, ocean, freight and brokerage typed rather than quoted.

$10,000 customs value. Duty 37.5% = $3,750. Formal MPF 0.3464% = $34.64 (above $33.58, under $651.50). Ocean HMF = $12.50. Freight $1,800, insurance $50, brokerage $175. Total $15,822.14.

$80,000 customs value. Duty 37.5% = $30,000. MPF 0.3464% = $277.12. Ocean HMF = $100. Freight $4,500, insurance $200, brokerage $350. Total $115,427.12.

Both totals are estimates from this site's landed-cost function, not a CBP invoice. Change the freight and the total changes. The duty rate does not.

A non-China comparison, so the China list is obvious: $25,000 of German machinery is 10% in this calculator, $2,500 of duty. The breakdown is 2.5% Column 1 plus 7.5% to reach the EU 10% net ceiling. There is no China Section 301 line.

Where to run your own shipment

Classification comes before the rate. Search the schedule on the HTS code lookup, then stack the origin in the tariff calculator. Category math, when you do not have a code yet, is the landed cost calculator.

If the origin is China, do not stop on this page. The China list rate, the 12.5% tier, and the live calculator preset to China are on tariffs from China. The written China stack is how to calculate import duty from China, and it points back to that same country page.

Confirm a binding rate at hts.usitc.gov or with the licensed broker who will file the entry.