Cross-Border Import Tariff, Landed Duty & Gross Margin Calculator

Import Tariffs & Landed Cost: Section 301, HTS Codes & Margin Math

You found a supplier offering widgets at $8/unit. You price at $24.99 retail, dreaming of 68% margins -- then the freight forwarder invoice arrives with a 25% Section 301 duty you never modeled, plus harbor fees, customs brokerage, and warehousing. Your $8 widget lands at $13.40, and the margin is 46% before advertising. Tariff math is where e-commerce P&Ls go to die, because the duty rate depends on the exact HTS classification -- and the difference between two plausible 10-digit codes can be 0% vs 25%.

The components of landed cost, in order: product cost (FOB), international freight (per-unit share of container/LCL), insurance, customs duty (HTS rate times customs value -- usually FOB + freight), Section 301 additional duties (25% on many China-origin goods across Lists 1-4A), harbor maintenance fee (0.125% of FOB for ocean), merchandise processing fee (0.3464%, min $31.67 / max $614.35), customs broker fee, domestic freight to warehouse, and warehousing/3PL receiving. Miss any two and your margin estimate is fiction. The Section 301 layer is the volatile one -- exclusion processes, list changes, and tariff actions have moved rates multiple times since 2018. Model scenarios, not single rates.

The strategic responses that work: HTS engineering (legitimate reclassification through product design changes -- e.g., material composition shifts that qualify for lower-duty codes; this is legal planning, misdeclaration is fraud), country diversification (Vietnam, India, Mexico carry different duty profiles, though substantial transformation rules police simple relabeling), de minimis ($800 duty-free threshold per shipment per person -- the business model behind direct-from-China pricing, though regulatory scrutiny is rising), and bonded warehouses/FTZs (defer or reduce duties). The calculator builds the full landed-cost stack from your inputs and shows margin at multiple duty scenarios.

First-time importers get surprised by the cash-flow timing too: duties are due when goods clear customs -- weeks before you sell a unit. A $50,000 shipment at 25% duty means $12,500+ cash out the door at the port, plus freight already paid. Budget working capital for the full landed cost upfront, not just the supplier invoice. And get a customs broker before you need one: the $150-$300 per-entry fee is trivial vs a misclassified shipment held for exam ($1,000+/day storage) or a penalty for negligence. The broker also keeps your HTS classifications defensible -- CBP can audit back 5 years.