Strait of Hormuz Monitor

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Strait of Hormuz: Facts, Glossary & Historical Closures

A quick reference for the world's most important oil chokepoint — the canonical numbers, the terms you'll see across this dashboard, and how the 2026 closure compares to past disruptions. Every figure links to its source. For the live status, see the dashboard.

Key facts

Length
~90 nautical miles (~167 km) [Wikipedia]
Narrowest width
~21 nautical miles (~39 km) [Wikipedia]
Shipping lanes
Two ~2-mile-wide lanes + a 2-mile buffer (Traffic Separation Scheme), in Iranian & Omani territorial waters [Wikipedia]
Oil flow
~20 million barrels/day of crude, condensate & products — the world's #1 oil chokepoint [US EIA]
Share of global oil
~20% of total world petroleum consumption / ~25-30% of seaborne-traded oil [US EIA]
Share of global LNG
~20% of global LNG (chiefly from Qatar) [US EIA]
Destination
~84% of crude exiting Hormuz is bound for Asia (China, India, Japan, South Korea) [US EIA]
Daily value
Roughly $1.2 billion of oil transits per day at ~$70/bbl [US EIA]
Main exporters
Saudi Arabia, UAE, Iraq, Kuwait, Qatar, Iran [US EIA]
Bypass capacity
Saudi East-West (~5 Mbpd) + UAE ADCOP (~1.5 Mbpd) + Iraq-Turkey — only ~3.5-5.5 Mbpd of spare vs ~20 Mbpd normal [US EIA]

How the 2026 closure compares to past disruptions

EventYearsWhat happenedOil-price impact
Arab oil embargo1973-74OPEC Arab members cut output & embargoed the US/allies after the Yom Kippur War.Oil price ~quadrupled (~$3 → ~$12/bbl)
Tanker War (Iran-Iraq)1984-88Iran & Iraq attacked ~450 merchant ships in the Gulf; US reflagged Kuwaiti tankers (Operation Earnest Will). Strait stayed open.Spikes & elevated war-risk premiums; no sustained closure
Gulf War1990-91Iraq's invasion of Kuwait removed Kuwaiti & Iraqi exports; Hormuz traffic disrupted but not closed.Brent ~doubled (~$17 → ~$36/bbl) then fell
Gulf of Oman tanker attacks2019Limpet-mine attacks on tankers near Fujairah/Hormuz amid US-Iran tensions; tankers seized.Brief ~4% price spikes; insurance premiums jumped
Suez / Ever Given2021A grounded container ship blocked the Suez Canal for 6 days, stranding ~$9.6B/day of trade (a different chokepoint).Brent +~4% during the blockage
Red Sea / Houthi attacks2024-25Houthi missile/drone attacks forced most carriers off the Bab-el-Mandeb / Suez route around Africa (a different chokepoint).Elevated freight & insurance; modest crude impact
Strait of Hormuz closure2026After the late-Feb US/Israel air war on Iran, Iran declared the strait closed (4 Mar 2026), mined & attacked shipping; ~1,550 vessels stranded.Brent topped $100 (4-yr high), peaked ~$118-120/bbl

Suez (2021) and the Red Sea (2024-25) are different chokepoints, included for severity context.

Glossary

Chokepoint
A narrow shipping passage that, if blocked, disrupts a large share of global trade. Hormuz is the world's most important oil chokepoint.
AIS
Automatic Identification System — VHF transponders that broadcast a ship's identity, position, course, and speed. The basis of live vessel tracking (and self-reported, so it can be switched off or spoofed).
MMSI / IMO number
MMSI is a 9-digit radio identifier (can change); the IMO number is a permanent 7-digit hull identifier used to track a ship across renamings and reflaggings.
Mbpd / Mbbl
Million barrels per day / million barrels. Hormuz normally carries ~20 Mbpd of oil.
VLCC / Suezmax / Aframax
Tanker size classes. A VLCC (Very Large Crude Carrier) holds ~2 million barrels; Suezmax ~1M; Aframax ~0.75M.
DWT
Deadweight tonnage — the total weight a ship can carry (cargo + fuel + stores), the standard measure of tanker capacity.
War-risk premium
An extra marine-insurance charge (a % of hull value, or a multiple of baseline) for sailing through a designated high-risk area. The market price of perceived danger.
P&I club
Protection & Indemnity club — a mutual insurer covering third-party liabilities (pollution, crew, collision). Withdrawal of P&I cover can effectively halt a voyage.
Joint War Committee (JWC) Listed Areas
A Lloyd's market list of waters deemed high war-risk; listing (e.g. the Gulf) triggers additional premium and shipowner notifications.
Dark fleet / ghost ship
Tankers that disable AIS ('go dark'), spoof positions, or use flag-of-convenience registries to move sanctioned or high-risk cargo undetected.
STS transfer
Ship-to-ship transfer — moving cargo between vessels at sea, often used to obscure a cargo's origin.
TSS
Traffic Separation Scheme — the IMO-designated inbound/outbound lanes that organize traffic through the strait.
Petroline (East-West Pipeline)
Saudi Aramco's pipeline carrying crude ~1,200 km from the Eastern Province to Yanbu on the Red Sea, bypassing Hormuz (~5 Mbpd capacity).
ADCOP
Abu Dhabi Crude Oil Pipeline — carries UAE crude from Habshan to the Fujairah export terminal on the Gulf of Oman, bypassing Hormuz (~1.5 Mbpd).
SPR
Strategic Petroleum Reserve — government-held emergency crude stocks (the US SPR sits in Gulf Coast salt caverns) that can be released to offset supply shocks.