Before You Quote That Landed Cost: How the Hormuz Closure Changes Every Calculation

The Strait of Hormuz carried 20 million barrels of oil per day and 20% of global LNG trade before Iran's IRGC declared it closed on March 2, 2026. Daily transits collapsed from roughly 120 to single digits, a 95% decline. Every importer running a landed cost model built on January 2026 assumptions is now working with dead numbers.

Here is what changed, what it costs, and how to recalculate.

The duty stack did not change. Everything around it did.

Your base HTS rate, your Section 301 exposure, your Section 232 surcharge: those are the same today as they were on February 27. The tariff schedule does not care about geopolitics. But the landed cost formula is more than the duty stack. It includes ocean freight, fuel surcharges, marine insurance, inland transport, and warehousing. Every one of those inputs spiked in March 2026.

Ocean freight surcharges: Container lines imposed emergency surcharges of $1,500 to $4,000 per TEU within days of the closure. A container from Asia that cost $2,200 in January now carries $4,000 to $7,000 in surcharges alone. That is not a rounding error. On a 40-foot container of industrial parts valued at $80,000, surcharges alone can add 5% to 8.75% to your landed cost before you touch a tariff line.

Marine insurance: War risk premiums surged from 0.25% to over 5% of hull value, a 20-fold increase. For a VLCC carrying $150 million in cargo, insurance costs jumped from $375,000 to $7.5 million per voyage. Those costs flow directly into freight rates.

Fuel surcharges: Diesel hit $4.83 per gallon in the US, triggering a 24.75% fuel surcharge across logistics networks. Brent crude moved from $67 to a peak near $126 per barrel. Every truck, every rail car, every last-mile delivery now costs more.

Transit time penalties: Rerouting around the Cape of Good Hope adds 10 to 14 days to transit times from Asia. Longer transit means more inventory in motion, higher carrying costs, and compressed planning windows for seasonal goods.

A worked example: electronics assembly from Shenzhen to Chicago

Take a shipment of printed circuit board assemblies, HS 8534.00, valued at $200,000 FOB Shenzhen.

January 2026 landed cost estimate:

• Base HTS duty rate: 0% (8534.00 enters duty-free for most classifications)
• Section 301 List 4A: 7.5% = $15,000
• Ocean freight (Shenzhen to Long Beach): $2,200 per FEU
• Fuel surcharge: 12% of freight = $264
• Marine insurance: 0.25% of cargo value = $500
• Inland transport (Long Beach to Chicago): $3,800
• Total non-duty logistics cost: $6,764
• Total landed cost: $221,764

March 2026 landed cost estimate (same shipment, same route):

• Base HTS duty rate: 0%
• Section 301 List 4A: 7.5% = $15,000
• Ocean freight: $2,200 base + $4,000 emergency surcharge = $6,200 per FEU
• Fuel surcharge: 24.75% of freight = $1,534
• Marine insurance: 3% of cargo value (elevated risk corridor) = $6,000
• Inland transport: $4,740 (diesel at $4.83/gallon)
• Transit delay carrying cost (14 extra days at 6% annual rate): $460
• Total non-duty logistics cost: $18,934
• Total landed cost: $233,934

The duty stack stayed identical. The landed cost jumped $12,170, a 5.5% increase driven entirely by logistics and energy disruption. For lower-value, high-volume goods like plastics or textiles, the percentage impact is far worse.

Petrochemical inputs are a hidden landed cost multiplier

The Hormuz closure did not just raise shipping costs. It disrupted the raw materials inside the products being shipped. The Middle East supplies roughly 30% of global seaborne LPG exports and 24% of global seaborne naphtha, both critical petrochemical feedstocks.

Indian polyethylene prices jumped 43% since the war started. Thai plastic resins rose 30% to 40%. South Korean ethylene production was cut by up to 50%. Force majeure declarations cascaded across Asia from Singapore to Taiwan to Japan.

If your product contains plastic resins, synthetic fabrics, rubber, solvents, packaging materials, or pharmaceutical intermediates, your input costs are rising independent of your freight costs. A manufacturer buying polypropylene resin at $1,200 per metric ton in January is now paying $1,308 to $1,680 per metric ton. That feeds directly into COGS before the product ever reaches a shipping container.

Fertilizer prices hit spring planting at the worst possible moment

Urea prices at New Orleans jumped from $475 to $680 per metric ton, a 43% spike. The Green Markets North America Fertilizer Price Index rose 31% from February 28 through mid-March. Gulf states collectively account for roughly 49% of global urea exports, 30% of ammonia exports, and 45% of global sulfur supply. All of it normally transits Hormuz.

For importers in the agricultural supply chain, this is a double cost hit: higher input prices for fertilizer-dependent products and higher freight costs to move them. The American Farm Bureau warned of risks to "food security and national security."

What to recalculate right now

If you are filing entries based on landed cost estimates from before February 28, 2026, those estimates are wrong. Here is what needs updating:

• Freight contracts: Any rate locked before March 1 is either expired or about to be. Get current quotes that include emergency surcharges. The constraint is structural until the strait reopens.
• Insurance line items: If your landed cost model uses a flat 0.25% for marine cargo insurance, replace it. Current war risk premiums are 20 times that level for any route touching the Persian Gulf.
• Input cost assumptions: If your product contains petroleum derivatives, resins, or fertilizer-intensive agricultural inputs, your COGS assumptions from Q4 2025 are stale. Factor in 15% to 43% increases depending on the commodity.
• Transit time buffers: Add 10 to 14 days for any shipment rerouting around the Cape of Good Hope. Recalculate carrying costs and delivery commitments.
• Fuel surcharges: Replace any flat fuel surcharge with the current 24.75% logistics network surcharge. This applies to ocean, rail, and truck legs.

The landed cost is not just the duty stack

Triangle calculates the full duty stack, including base HTS rate, Section 301, Section 232, Section 122, and active AD/CVD orders, in a single API call with response times under 2 seconds. But the duty stack is one input in a landed cost formula that just got rewritten by a war 7,000 miles from your warehouse.

The companies that recalculate now will reprice accurately, renegotiate supplier terms with current data, and identify sourcing alternatives before their competitors do. The companies that wait will discover the gap on their next CBP liquidation statement.