How to Calculate US Import Duty in 2026 (With a Worked Example)

2026-11-12

2026 has been a hard year for anyone who keeps a duty spreadsheet. A tariff program was struck down, a temporary surcharge came and went, and new duties took effect. The arithmetic itself hasn't changed much, though. What changed is how many lines you need to check. Here's the method I use, with a fully worked example.

The rule I built DutyCite's calculator on: every rate gets an official source and an as-of date, and the math is shown line by line.

Disclaimer: This is general information, not customs brokerage, legal advice or a binding classification. Treat the numbers as estimates. For a classification you can rely on, get a CBP binding ruling or use a licensed customs broker.

What changed in 2026 (the short version)

• IEEPA tariffs ended. On Feb 20, 2026 the Supreme Court held in Learning Resources, Inc. v. Trump that "IEEPA does not authorize the President to impose tariffs" (Supreme Court opinion). Executive Order 14389, signed the same day, ordered collection to stop (Federal Register). CBP stopped collecting IEEPA duties on goods entered on or after 12:00 a.m. ET Feb 24, 2026 (CBP CSMS #67834313).
• A Section 122 surcharge ran for 150 days. Proclamation 11012 put a 10% surcharge on most imports from Feb 24, 2026 "through 12:01 a.m. eastern daylight time on July 24, 2026" (Federal Register).
• New Section 301 duties started the same day. USTR's forced-labor action added 10% or 12.5% on products of 60 economies, for goods entered on or after 12:01 a.m. ET July 24, 2026 (Federal Register). More detail is in Section 301 tariffs in 2026.
• Section 232 metals duties now apply to full value. From Apr 6, 2026 they apply "to the full customs value of the imported product" (Federal Register). See how Section 232 tariffs stack.

The method, in five steps

Step 1: Get the 10-digit HTS code

Everything depends on it. If you're not sure, start with my HTS lookup guide or the /hts tool, and remember that the legal rate sits on the 8-digit line.

Step 2: Confirm the country of origin and the customs value

Origin decides which Chapter 99 lines apply. Duty is assessed on customs value, which is usually the transaction value. Valuation has its own rules, so if you're unsure what goes into the value, ask a broker.

Step 3: Apply the base (Column 1 General) rate

Use the rate from the live USITC HTS, or a "Special" rate if you actually qualify for a trade program and claim it.

Step 4: Add the Chapter 99 duties for that code and origin

These are the add-ons: Section 301 (country- and product-specific), Section 232 (product-specific, sometimes origin-specific) and others. Each one has its own heading, rate and exemptions. They don't all stack the same way. Some exempt each other, and some cap the total. What a stacked tariff rate includes goes through the logic.

Step 5: Add the fees: MPF and, for ocean freight, HMF

• Merchandise Processing Fee (MPF): 0.3464% of value on formal entries (19 CFR 24.23). For FY2027 (entries from Oct 1, 2026) the minimum is $34.58 and the maximum $670.86 (Federal Register).
• Harbor Maintenance Fee (HMF): 0.125% of value on commercial cargo unloaded from a commercial vessel at a covered port (19 CFR 24.24).

MPF and HMF fees in 2026 covers minimums, maximums and exemptions.

Worked example: cotton T-shirts from Vietnam

Assumptions: men's knit cotton T-shirts, HTS 6109.10.00. Product of Vietnam. Customs value $20,000. Arrives by ocean. Formal entry. No trade-program claim. As of Nov 12, 2026.

That's about 29.5% of the goods' value, made up of $5,800.00 in duties and $94.28 in fees.

Some things I checked before trusting that table:

• Is 6109.10.00 exempt from the Vietnam duty? The HTS note that lists exemptions (U.S. note 52) mentions 6109.10.00 only for Guatemala, El Salvador and Jordan, not Vietnam.
• Was this an old IEEPA or Section 122 line? Not on this date. Both programs ended before July 24, 2026 (see above).
• Antidumping or countervailing duties? Not checked in this example. They're product- and producer-specific and sit outside this math, so always check CBP's AD/CVD page.

Rates change, sometimes with only a few days' notice. Re-check every line on the date you import. The calculator shows each line's as-of date for that reason.

Common mistakes

1. Forgetting Chapter 99. In the example above, Chapter 99 is 43% of the total duty.
2. Mixing up the fiscal years. MPF limits change on Oct 1 each year.
3. Adding HMF to air shipments. HMF is for cargo loaded or unloaded from a commercial vessel.
4. Assuming a trade program wipes out everything. Many Chapter 99 duties still apply to goods that qualify for special rates. Read each note.

Doing it faster

You can do all of this by hand from the sources above, and I'd encourage you to do it once. After that, DutyCite's calculator runs the same steps and shows each line with its citation. Developers can call it from code or an agent. See the docs and pricing.

Checked Nov 12, 2026. Rates change, so verify before importing.

References

1. Supreme Court of the United States, Learning Resources, Inc. v. Trump, No. 24-1287 (Feb 20, 2026). https://www.supremecourt.gov/opinions/25pdf/24-1287_4gcj.pdf
2. Federal Register, Executive Order 14389, "Ending Certain Tariff Actions," 91 FR 9437 (Feb 25, 2026). https://www.federalregister.gov/documents/2026/02/25/2026-03832/ending-certain-tariff-actions
3. CBP, CSMS #67834313, "Ending Collection of International Emergency Economic Powers Act Duties." https://content.govdelivery.com/accounts/USDHSCBP/bulletins/40b11c9
4. Federal Register, Proclamation 11012, "Imposing a Temporary Import Surcharge To Address Fundamental International Payments Problems," 91 FR 9339 (Feb 25, 2026). https://www.federalregister.gov/documents/2026/02/25/2026-03824/imposing-a-temporary-import-surcharge-to-address-fundamental-international-payments-problems
5. Federal Register, USTR, "Notice of Actions in Section 301 Investigations ... Forced Labor," 91 FR 47318 (Jul 28, 2026). https://www.federalregister.gov/documents/2026/07/28/2026-15181/notice-of-actions-in-section-301-investigations-of-acts-policies-and-practices-of-various-economies
6. Federal Register, Proclamation 11021, "Strengthening Actions Taken To Adjust Imports of Aluminum, Steel, and Copper Into the United States," 91 FR 18201 (Apr 9, 2026). https://www.federalregister.gov/documents/2026/04/09/2026-06960/strengthening-actions-taken-to-adjust-imports-of-aluminum-steel-and-copper-into-the-united-states
7. USITC, Harmonized Tariff Schedule (2026 Revision 23). https://hts.usitc.gov/
8. eCFR, 19 CFR 24.23, Fees for processing merchandise. https://www.ecfr.gov/current/title-19/chapter-I/part-24/section-24.23
9. Federal Register, CBP, "Customs User Fees To Be Adjusted for Inflation in Fiscal Year 2027," 91 FR 48398 (Jul 31, 2026). https://www.federalregister.gov/documents/2026/07/31/2026-15530/customs-user-fees-to-be-adjusted-for-inflation-in-fiscal-year-2027
10. eCFR, 19 CFR 24.24, Harbor maintenance fee. https://www.ecfr.gov/current/title-19/chapter-I/part-24/section-24.24
11. CBP, Antidumping and Countervailing Duties (AD/CVD). https://www.cbp.gov/trade/priority-issues/adcvd