US Tariffs Explained
How US import duty actually works, and a running record of every change to the Harmonized Tariff Schedule. Written by the people who build and maintain HTS Hero's tariff calculator.
The essentials of US tariffs
What tariffs are, how US duty is calculated, and how the programs stack on one import.
What Are Tariffs? How US Import Tariffs Work in 2026
What are tariffs? A tariff is a tax on imported goods, paid by the US importer to CBP. Who pays, how rates are set, and which tariffs apply in 2026.
· 5 min read
Tariff GuidesHow US Tariffs Are Calculated: Formula and 2026 Examples
How to calculate US import duty: HTS base rate plus every Chapter 99 tariff, then MPF and HMF fees, with four worked examples from October 2026.
· 6 min read
Tariff GuidesTariff Stacking Rules 2026: Which US Tariffs Add Up
US tariff stacking rules in 2026: Section 301 China stacks on Section 232, forced-labor and Brazil duties switch off, and how Canada 338 and deal rates combine.
· 6 min read
Tariff UpdatesLatest US Tariff Changes 2026: Every Change in One Table
The latest US tariff changes as of October 2026: pharma list update, Canadian import bans, Section 338 and drone tariffs, and every 2026 change by date.
· 4 min read
Latest in Tariff Updates
New US tariffs, exemptions and changes as they're announced, with what they mean for your imports and the legal text behind them.
Reciprocal Tariff Food Exemptions: The November 2025 List
From November 13, 2025, 237 food and farm subheadings and 11 partial exemptions under 9903.02.78 left the reciprocal tariff. What was covered, and why it ended.
· 3 min read
De Minimis Suspension in 2026: What $800 Imports Pay Now
The $800 de minimis exemption has been suspended since August 29, 2025. Low-value imports now pay full duty, and the suspension holds through 2026.
· 4 min read
Section 301 China Exclusions: Extended to November 9, 2026
The 178 Section 301 China exclusions under 9903.88.69 and 9903.88.70 expire at 11:59 p.m. ET on November 9, 2026. What they cover and what to plan for.
· 3 min read
US Tariffs on India: The 25% Russian Oil Duty and After
The US 25% Russian oil tariff on India (9903.01.84) ran from August 27, 2025 to February 7, 2026. How it worked, its exemptions, and what India pays now.
· 3 min read
Latest in HTS Revisions
Every revision of the 2026 Harmonized Tariff Schedule, broken down: which Chapter 99 headings changed, when, and which imports are affected.
2026 HTS Revision 20: Pharma Tariff List and R&D Exemption
2026 HTS Revision 20 grew the Section 232 pharmaceutical tariff list to 149 lines and exempted clinical trial and R&D use (9903.04.70) from September 29, 2026.
· 3 min read
2026 HTS Revision 19: Section 338 Canada Lists Expanded
2026 HTS Revision 19 widened the 50% Section 338 tariff on Canada from September 15, 2026, adding furniture, cheese and boats and stacking it on Section 232.
· 3 min read
2026 HTS Revision 18: Section 232 Drone Tariffs, Beef Quota
2026 HTS Revision 18 added Section 232 drone tariffs of 25% or 100% from September 3, 2026, plus a 300,000-ton lean beef quota and Section 301 code fixes.
· 4 min read
2026 HTS Revision 17: 50% Section 338 Tariff on Canada
2026 HTS Revision 17 added a 50% Section 338 tariff on about 550 listed Canadian products from August 22, 2026, owed even when USMCA is claimed.
· 3 min read
2026 HTS Revision 16: Section 201 Quartz Safeguard Tariff
2026 HTS Revision 16 added a Section 201 safeguard on quartz countertops and slabs from August 15, 2026: 25% within the quarterly quota, 50% above it.
· 3 min read
2026 HTS Revision 15: UK Patented Pharmaceuticals Cut to 0%
2026 HTS Revision 15 (August 3, 2026) cut the Section 232 tariff on UK patented pharmaceuticals under 9903.04.63 from 10% to 0%, back to July 31.
· 2 min read
See every tariff on your import, line by line
Enter an HTS code and a country of origin. HTS Hero stacks the base rate with every Chapter 99 tariff that applies and shows you the math.
What you get
- Section 232, Section 301 and every other program, stacked correctly
- Exemptions and trade preferences that could apply
- Compare the same product from every country