Tutorials
How to install and use each shape of the toolchain — web calculator, npm package, browser extension, desktop app and open datasets — with working code and live examples you can rerun.
Web calculator
- How to Use the US Tariff Calculator: A Step-by-Step Walkthrough
A 5-step walkthrough of the free US tariff calculator: set origin and transport mode, enter value, find the HTS code, read the stacked duties, and get a per-unit landed cost with margin back-solve.
Who this is for · Importers, e-commerce sellers and anyone pricing goods for the U.S. market — no technical background needed.
npm package & CLI
- us-tariff-lookup: npm Package & CLI Tutorial (With Working Code)
Install us-tariff-lookup, run the npx CLI for searches and stacked duty calculations, then call calculateLandedCost from Node — an Express example, versioning guidance and disclaimer display included.
Who this is for · Node.js developers adding tariff math to their own apps, scripts, spreadsheets or AI agents.
Browser extension
- How to Install and Use the US Tariff Lookup Browser Extension
Install the free US Tariff Lookup extension, then look up HTS codes and stacked duty rates three ways: toolbar popup, right-click on any selected text, and the address bar. Works offline, sends nothing anywhere.
Who this is for · Sellers, sourcing agents and buyers who want duty answers while browsing supplier, marketplace or HTS pages.
Desktop app
- US Tariff Lookup Desktop App: Download, Install and First Steps
Download the free US Tariff Lookup desktop app for Windows, macOS or Linux, verify the SHA256 checksum, get past the unsigned-app warning, and run your first offline stacked-duty lookup.
Who this is for · Anyone who wants offline tariff lookup as a desktop app — freight forwarders, brokers and sellers working across machines.
Open datasets
- Using the Open US Tariff Datasets in Excel, Python and Google Sheets
Which open US tariff dataset to use for which job — per-code CSV, economy tiers, Section 232 layers, the full HTS table — and how to load them in Excel, pandas and Google Sheets, with the CC BY 4.0 citation format.
Who this is for · Analysts, developers and researchers who want the raw tariff rates — in Excel, pandas, Google Sheets or their own pipeline.
Source repositories and download links for every project live on the open source page; knowledge-length guides on how tariffs work are in Guides.