We compared HTS Hero with the best-known duty and tariff tools, from Flexport and enterprise platforms like Avalara, Zonos and Descartes to free single-lookup calculators. Here's what each one does well, where it falls short, and which to pick for your situation.
No demo, no sales call, no contract. Last checked .
How we ranked
What makes a tariff calculator good
Five questions decide whether a calculator's number is one you can price, file or audit against.
01
Is the total complete?
The duty CBP charges is the HTS base rate plus every Chapter 99 tariff that applies, minus exemptions, plus fees. A calculator that leaves out the base rate or lumps tariffs together gives you a number you can't check.
02
Is it current, and can you tell?
The Harmonized Tariff Schedule has been revised 20 times so far in 2026. We looked for tools that say which revision their data reflects and keep a record of updates.
03
Can it look backward?
Auditing an entry, or checking a refund, means knowing the duty that applied on the day the goods entered.
04
Does it scale to a catalog?
Importers have dozens or thousands of products. We looked at bulk upload, country comparison and seeing which products a change affects.
05
Can you just start?
Published prices and self-serve plans, versus demos, sales calls or becoming a freight customer first.
The rankings
12 US tariff calculators, ranked
1
HTS Hero
US tariff calculator and auditor
Best overall for US importers
A US tariff calculator built for importers who need the exact number: every Chapter 99 tariff stacked line by line with its legal source, entry audits by date, duty over time, alerts when a tariff change hits your products, and results by API and MCP for your own systems.
Strengths
Every Chapter 99 tariff as its own line, with the heading and U.S. note behind it
Audit past entries: the duty on the entry date, from the HTS revision in force that day
Duty Over Time shows how a product's duty changed across revisions
Alerts when a tariff change hits your products, with what it costs each one
Published prices, monthly plans, start in a minute with no demo or contract
Tariff results by API and MCP, built into your ERP, TMS or internal tools
Limitations
US imports only
Verified historical rates start in April 2026
Price
Free, then from $14.99/mo
Best for
Importers, brokers and compliance teams who need exact, auditable US duty
The best-known free tariff calculator, run by the freight forwarder Flexport. The free tool handles single lookups; bulk upload, alerts and its other Pro features are for Flexport customers.
Strengths
Well-known brand with a polished interface and trade map
Free for 5 searches, then a free account
Entry-date rates back to January 1, 2025
Applies trade agreements such as USMCA automatically
Metal-content and melt-country questions for Section 232
Public changelog of calculation updates
Hundreds of dated worked examples
Free IEEPA tariff refund calculator
Limitations
Bulk upload, alerts and country comparison require becoming a Flexport client
No published price for Pro
One calculation at a time on the free tool
Its FAQ says not all Chapter 99 programs are supported
We found no handling of the September 29, 2026 Canadian import bans
Built as a funnel for Flexport's freight and customs business
Price
Free; Pro for Flexport clients
Best for
Quick one-off estimates, and Flexport freight customers
Avalara AvaTax Cross-Border calculates or estimates customs duty and import tax in online shopping carts, with HS-6 or HS-10 classification, for retailers selling across borders. It's built into stores and marketplaces rather than used as a standalone calculator.
Strengths
Duty and tax at checkout for many countries
Large ecommerce and marketplace integrations
HS classification services
Limitations
Designed for checkout estimates across many countries; US Chapter 99 itemization isn't documented
No published prices found
Price
Contact Avalara
Best for
Retailers that need duty and tax at checkout, in many countries
Landed cost at checkout for cross-border ecommerce
Zonos calculates and can guarantee landed cost at checkout for cross-border ecommerce, across 200+ countries and territories, with plugins for the major store platforms.
Strengths
Guaranteed landed cost at checkout
200+ countries and territories
Store platform plugins
Limitations
Designed for store checkouts, with no documented US Chapter 99 breakdown
No published prices on its landed cost page
Price
Not published
Best for
Cross-border stores that want guaranteed landed cost at checkout
Enterprise trade content for classification and tariff research: duty and tariff data for 152 countries and territories and 600,000 US and EU binding rulings, used by brokers, forwarders and large compliance teams.
Strengths
Duty data for 152 countries and territories
600,000 US and EU binding rulings
Established with brokers and enterprises
Limitations
Enterprise pricing, from about $750 per user
Built for many countries, more than most US importers need
Price
From about $750 per user
Best for
Large compliance teams researching tariffs in many countries
A global import duty calculator and API covering 100+ destinations. Free use needs registration and is capped at 5 calculations a day; paid plans are priced by API calls.
Strengths
Global coverage
Inexpensive API pricing
Published prices
Limitations
Registration needed even for free use, capped at 5 a day
US additional tariffs come back as one layer, with no Chapter 99 breakdown
Its US tariff update log was last updated May 29, 2025
Price
From £9.99/mo
Best for
Developers who need cheap duty estimates for many countries
A free US tariff calculator from Flowyth Co of Austin, with an AI classifier, entry dates, a 200+ country comparison and Compliance Radar alerts in beta. The calculator needs no login; plan prices appear only after you log in.
Strengths
Broad free feature set with no login
Entry dates and a 200+ country comparison
AI classifier
Covers the 2026 Section 301, 232 and 338 programs
Limitations
Plan prices aren't published
No exemption questions: uncertain tariffs are shown as "Potential" and left out of the total
Trade agreements only in the paid area
Its calculator banner said "Revision 10" on October 6, 2026, when the current revision was 20
We found no handling of the September 29, 2026 Canadian import bans
Price
Free calculator; paid pricing not published
Best for
Teams that want a free calculator plus AI classification
A free tariff calculator from Gateway Lines, a New York freight forwarder, with current 2026 data, Chapter 99 citations, bulk upload, AI classification and a free MCP server. It calculates current-day entries only.
Strengths
Current 2026 data, reviewed within 24 to 48 hours
Chapter 99 citations, including the Canadian import bans
Bulk upload and country comparison on a free account
Free MCP server and a ChatGPT app
Limitations
Current-day entries only: no past entry dates or history
Alerts are policy emails, not tied to your products
A free tariff simulator from a freight forwarder and customs broker, with each tariff as a separate line and an entry-date input. Single lookups, no account.
Strengths
Free with no account or limits
Entry dates and current 2026 programs
Itemized tariff lines with a version stamp
Free public API
Limitations
One product at a time, with no catalog, CSV or alerts
Prices some banned Canadian goods, such as beer at 60%
Trade agreements and annex exemptions not evaluated on the web page
An API-first tariff data service from Brightworks Digital of Singapore. The free calculator shows the effective rate; the breakdown, legal sources and history sit behind an email or a paid plan from $99 a month.
Strengths
Strong API with an MCP server
Results cite the HTS subheading and CBP measures
Published pricing
Limitations
Paid plans start at $99 a month
No classification help
Its changelog shows the September 29, 2026 Canadian import bans added about 5 days late
Price
Free calculator; from $99/mo
Best for
Developers building duty rates into their own software
A simple free tariff calculator from AMZ Prep, a 3PL for Amazon sellers. Easy to use for a rough number, with a lighter breakdown than a full duty calculator.
Strengths
Free and simple
Written for Amazon and ecommerce sellers
Limitations
Its rates exclude the standard MFN duty, so you add the base rate yourself
When we checked it listed a 10% China reciprocal tariff, though the IEEPA tariffs ended in February 2026
Flat country rates: goods from China show 25% whatever the HTS code
Free to tryYou can calculate a real duty without paying.
YesFree to start, no sign-up
Yes5 free searches, then a free sign-up
PartlyDeveloper sandbox and trial; no public calculator
PartlyFree US quoter, about 5 quotes
Partly14-day trial, business email, 1 to 2 day wait
Start without a demo or sales callSign up and use every plan yourself, with no demo, contract or freight account.
YesEvery plan is self-serve, with no demo or contract
PartlyFree tool is self-serve; Pro needs a Flexport client account
NoCross-border is enabled by Avalara, after a demo
PartlySelf-serve on Shopify; otherwise through sales
NoDemo or contact form
Pricing publishedEvery paid plan's price is on the website.
Yes
NoPro has no published price
No
Partly$2 per order + 10% of duties and taxes
No
Every Chapter 99 tariff, line by lineThe base rate plus Section 232, Section 301 and every other additional duty, each as its own line with exemptions applied.
YesEach tariff on its own line, with its Chapter 99 heading and legal note
PartlyBy tariff type; its FAQ says not all Chapter 99 programs are supported
NoOne import duty line in the API
NoOne duty total
PartlyChapter 99 data, for customers
Trade agreements and preference programsClaim USMCA, CAFTA-DR, KORUS and other programs and see the preferential rate.
YesUSMCA, CAFTA-DR, KORUS and every program on the line
YesApplied automatically when eligible
Yes
Partly
Paid plan
Exemption questions that change the dutyAnswer the facts that unlock exemptions (metal content, generics, donations and more) and see the new total.
YesAnswer each question and see the new total
YesMetal content, melt country and U.S. content
No
Not found
Partly
Audit past entries by dateCalculate the duty that applied on an entry date, to check what you paid.
YesEntry audits, with verified rates back to April 2026
YesBack to January 1, 2025, per its FAQ
PartlyA date field in the API
No
Not found
Duty over timeSee how a product's duty changed across HTS revisions.
YesDuty Over Time, revision by revision
Not found
No
No
Not found
Alerts when a tariff change hits your productsLoad your catalog once and hear when a change affects it, with the duty impact on each product.
Paid planTariff Tracker alerts, with the cost to each product
Customers onlyPro alerts, for Flexport clients
NoTariff news by blog and webinar
Customers only
PartlyRegulatory update notices
Compare countries of originThe same product's duty from several countries, side by side.
Yes
Customers onlyPro, for Flexport clients
No
No
Paid plan
Bulk upload (CSV)Add many products at once.
Paid planTariff Tracker
Customers onlyPro, up to 500 rows
Customers onlyBy SFTP or API
Customers onlyBulk classification
Paid plan
HTS classification helpGuidance to find and document the right HTS code for a product.
Paid planHTS Hero Classify, with CROSS rulings
YesHTS search and AI classification
Customers onlyAI plus human review, up to 24 hours
YesZonos Classify
Paid planAI-assisted research
API, MCP and ERP/TMS integrationGet tariff results inside your ERP, TMS, internal tools or AI assistant.
On requestAPI and MCP; plugs into ERP, TMS and internal tools
NoNo public tariff API
Customers onlyREST API and MCP servers, for customers
Paid plan
On requestERP data feeds
Public changelog of rate updatesA dated record of every change to the tool's tariff data.
Yes
Yes
No
PartlyProduct changelog only
YesWeekly update notices
Checked against each tool's public website on October 6, 2026. “Not found” means we couldn't find it on the vendor's public pages, so we don't count it either way.
API and MCP
Plug HTS Hero into your ERP, TMS and internal systems
Get every tariff, exemption and fee for an import wherever you price, plan or file: in your ERP, your TMS, your own tools or an AI assistant. We'll set it up with you.
Tariff results by API, for your ERP, TMS or internal tools
An MCP server, so AI assistants can calculate duty
The same line-by-line results as the calculator
Start free
Try HTS Hero now. No demo required.
Enter an HTS code and a country of origin and see the full US duty: the base rate, every Chapter 99 tariff and the fees. When you need unlimited calculations, it's $14.99 a month.
Free to start, no sign-up: every tariff on your import, line by line
Published prices, monthly plans, no contract
No demo, no sales call, no freight account
Start in about a minute
FAQ
Questions
What is the best US tariff calculator?
For US importers who need an exact, auditable number, we rank HTS Hero first: it itemizes every Chapter 99 tariff with its legal source, lets you claim trade agreements and exemptions, audits past entries by date, shows duty over time, alerts you when a tariff change hits your products, and delivers results by API and MCP, on self-serve plans with published prices. We make HTS Hero, so we've linked the sources for every other tool on this page.
Is there a free US tariff calculator?
Yes, several. HTS Hero is free to start with no sign-up and shows the full line-by-line breakdown, and GingerControl, Flexport, Gateway Lines, Airlift USA and AMZ Prep all offer free calculators with different limits and levels of detail.
Does the US government have an official tariff calculator?
The US International Trade Commission publishes the Harmonized Tariff Schedule at hts.usitc.gov, which lists every rate and the Chapter 99 notes. It doesn't add up the total duty for you, which is why importers use calculators that stack the base rate and each additional tariff.
Why do tariff calculators give different answers?
Usually for one of four reasons: some leave out the base (MFN) rate, some run on an older HTS revision, some skip exemptions or partial-value rules such as metal content under Section 232, and some estimate from a product category instead of the HTS code.
Can a tariff calculator tell me what I owed on a past entry?
Only if it calculates by entry date. HTS Hero uses the HTS revision in force on the date you pick and shows how the duty changed over time. Flexport's simulator keeps rates back to January 1, 2025, and GingerControl and Airlift USA's free simulator also accept an entry date.
HTS Hero makes one of the tools on this page. We checked every claim about other tools against their public websites on October 6, 2026 and link our sources below. If something has changed, email [email protected] and we'll update it.
