Duty Simulator vs Flexport Tariff Simulator: Which is Right for You?
Flexport launched their Tariff Simulator in 2025, and with their massive logistics brand behind it, you've probably seen it mentioned. But comparing it to Duty Simulator is like comparing a calculator to an accountant—they solve fundamentally different problems.
Disclosure: We built Duty Simulator, so we're biased. But we'll give you an honest breakdown of when Flexport's tool makes sense and when you need something more powerful.
Key Takeaways
- Flexport Tariff Simulator is a free duty calculator for importers who already know their HTS codes
- Duty Simulator is an AI classification tool for customs brokers who need to determine HTS codes
- If you're a shipper estimating landed costs, Flexport's calculator may be enough
- If you're a customs broker doing classification work, you need Duty Simulator
- They're complementary, not competitive—but for professional classification work, there's no comparison
Quick Comparison
| Feature | Duty Simulator | Flexport Tariff Simulator |
|---|---|---|
| Purpose | AI-powered classification | Duty cost calculation |
| Primary User | Customs brokers | Importers/shippers |
| AI Classification | ✅ Yes | ❌ No |
| Explainable Reasoning | ✅ GRI-based logic | ❌ N/A |
| Email Processing | ✅ Automatic | ❌ No |
| Cost Calculation | ✅ Basic | ✅ Comprehensive |
| MPF/HMF | ✅ Included | ✅ Included |
| Section 301 Tariffs | ✅ Real-time | ✅ Real-time |
| Reasonable Care | ✅ Audit-ready | ❌ No |
| Pricing | Subscription | Free |
| Best For | Professional brokers | Quick cost estimates |
What Problem Are You Solving?
Before diving into features, let's be clear about use cases:
"I have a product and need the correct HTS code" → Duty Simulator
This is classification work. It requires:
- Understanding the product's composition, function, and use
- Applying GRI rules correctly
- Documenting reasonable care for CBP compliance
- Professional judgment on ambiguous classifications
"I know my HTS code and need to estimate duties" → Flexport Tariff Simulator
This is calculation work. It requires:
- Entering the HTS code you already have
- Inputting value and country of origin
- Getting duty rates and fees
These are different problems. Flexport's tool doesn't help you figure out the HTS code—it assumes you already know it.
Flexport Tariff Simulator: Overview
What It Does
Flexport's Tariff Simulator is a free, web-based calculator that estimates US import duties. You enter an HTS code, country of origin, and product value, and it returns:
- Base duty rate
- Section 301 tariffs (if applicable)
- Merchandise Processing Fee (MPF)
- Harbor Maintenance Fee (HMF)
- Total estimated landed cost
It's polished, fast, and backed by Flexport's logistics expertise.
What It Does Well
✓ Free — No account required, no cost
✓ Fast calculations — Instant duty estimates
✓ Current rates — Includes 2026 tariff updates
✓ HTS catalog — Searchable code database
✓ Professional UI — Clean, enterprise-quality interface
✓ Trusted brand — Flexport's logistics credibility
Where It Falls Short
✗ No classification — You must already know the HTS code
✗ No AI analysis — Can't determine codes from product descriptions
✗ No documentation — Doesn't support reasonable care requirements
✗ No email processing — Manual entry only
✗ No workflow integration — Not built for broker operations
✗ Shipper-focused — Designed for importers, not professionals
Who Should Use It
- Importers estimating costs before purchasing
- Businesses doing quick landed-cost calculations
- Anyone who already knows their HTS codes
- Logistics teams validating freight quotes
Duty Simulator: Overview
What It Does
Duty Simulator is an AI-powered classification tool built for customs brokers. It takes product descriptions—from emails, commercial invoices, or packing lists—and determines the correct HTS code with explainable reasoning.
The core difference: Duty Simulator figures out the code. Flexport's tool calculates what a code costs.
Key Features
- AI Classification: Analyze product descriptions and return HTS codes
- Explainable Reasoning: See the GRI rules and logic behind each classification
- Email Processing: Forward broker emails, get classifications back automatically
- Reasonable Care: Documentation that supports CBP compliance audits
- Duty Calculation: Yes, we calculate duties too—but that's secondary to classification
What Duty Simulator Does Well
✓ AI-powered classification — Determine codes, not just look them up
✓ Explainable reasoning — GRI rule citations for every classification
✓ Email automation — Process incoming broker emails automatically
✓ Reasonable care — Audit-ready documentation for CBP
✓ Broker workflows — Built for how customs brokers actually work
✓ Complex products — Handles ambiguous classifications with analysis
Where We're Still Growing
✗ Not free — Subscription pricing for professional use
✗ US-focused — Optimized for HTS, not global tariff codes (yet)
✗ Newer tool — Less brand recognition than Flexport
Who Should Use It
- Customs brokers handling classification work
- Trade compliance teams ensuring reasonable care
- Import specialists dealing with complex products
- Anyone who needs to determine HTS codes, not just calculate them
The Flexport Scale Advantage
Let's be honest about what Flexport has that we don't: massive scale.
Their website says "Trusted by 10,000+ businesses." They're one of the largest digital freight forwarders in the world. Their tariff simulator is a lead-generation tool backed by billions in venture capital.
What this means for you:
- Flexport's calculator will always be free—it drives people to their logistics services
- They have resources to keep rates updated and maintain the tool
- The brand carries weight when sharing estimates with clients
What it doesn't mean:
- That their calculator can classify products (it can't)
- That it's built for customs brokers (it isn't)
- That free = best for professional use (it's not)
When to Use Each Tool
Use Flexport Tariff Simulator When:
- You already have the HTS code and need a quick cost estimate
- You're an importer comparing suppliers across countries
- You want a free tool for occasional use
- You need to show a client estimated landed costs
Use Duty Simulator When:
- You need to determine the HTS code for a product
- You're doing professional classification work
- You require reasonable care documentation
- You want AI to process classification emails automatically
- You're a customs broker serving multiple clients
Use Both When:
Here's a secret: you can use both.
- Use Duty Simulator to classify the product and get the HTS code
- Use Flexport's calculator to show clients estimated landed costs
They're complementary tools. But if you're choosing one for professional customs work, it's Duty Simulator.
Feature Deep Dive: Classification vs. Calculation
Flexport: Enter Code, Get Rate
Input: HTS 8471.30.0100, China, $10,000 value
Output:
- Duty Rate: 0%
- Section 301: 25%
- MPF: $30.17
- Total: $2,530.17
Simple. Fast. Useful for cost planning.
Duty Simulator: Describe Product, Get Code
Input: "Laptop computer, 15.6 inch display, Intel i7 processor,
16GB RAM, 512GB SSD, manufactured in China"
Output:
- HTS Code: 8471.30.0100
- Reasoning: Classified under GRI 1 as automatic data processing
machine. Portable unit with keyboard and display integrated
into same housing qualifies under 8471.30 (portable automatic
data processing machines). Weight under 10kg confirms portable
classification.
- Confidence: High
- Duty Rate: 0% base + 25% Section 301 = 25%
The reasoning is the value. It's what reasonable care requires.
Frequently Asked Questions
Can Flexport's tool classify products?
No. It's a calculator that requires you to input the HTS code. It has a searchable catalog, but searching for "laptop" gives you a list of codes—you still need to pick the right one.
Is Flexport free? What's the catch?
Yes, it's free. The "catch" is lead generation—they want importers to use it and then sign up for Flexport's logistics services. That's a reasonable business model, not a scam.
Can Duty Simulator calculate duties like Flexport?
Yes. Once we classify a product, we calculate duties, fees, and total landed cost. It's just not our primary value proposition.
Which is more accurate for duty rates?
Both should be accurate—they pull from the same official sources. Accuracy in duty calculation isn't the differentiator; accuracy in classification is.
Should customs brokers use Flexport's tool?
For quick client estimates? Sure. For classification work? No. It doesn't do classification.
The Bottom Line
Flexport Tariff Simulator is an excellent free calculator for importers who know their HTS codes and need cost estimates. It's polished, current, and backed by a trusted brand.
Duty Simulator is a professional classification tool for customs brokers who need to determine HTS codes with explainable reasoning and reasonable care documentation.
They solve different problems.
If your job is calculating costs from known codes, Flexport's free tool is great. If your job is classifying products for clients, you need Duty Simulator.
Try Duty Simulator
Ready to see AI-powered classification in action? Start your free trial and experience the difference between calculation and classification.