The question
How Wide Is the Strait of Hormuz?
21 nautical miles (about 39 kilometres) at the narrowest point. Ships don’t get all of it: they follow two one-way lanes about 2 nautical miles wide each, with a separation zone between them, so the working channel is far narrower than the map suggests.
21 nautical miles.
At its narrowest the Strait of Hormuz measures 21 nautical miles from shore to shore, about 39 kilometres. That’s the figure every other page on this site uses, and it runs between the Musandam peninsula in Oman and the Iranian coast near Bandar Abbas. The Persian Gulf opens out to the west and the Gulf of Oman to the east, so the strait is the pinch point between two much wider bodies of water.
The distance is small enough that a land-based missile or a fast boat launched from either shore can reach a ship in the middle. It’s also less than twice the 12 nautical miles that Iran and Oman each claim as territorial sea, which is why the two claims overlap here. Who controls the strait covers what that means.
Six miles of marked channel.
Ships can’t use the full width. The IMO Traffic Separation Scheme sets up an inbound lane and an outbound lane, each about 2 nautical miles wide, and puts a separation zone of roughly 2 nautical miles between them. Together that’s about 6 nautical miles of marked channel inside a strait of 21.
The buffer exists so that a ship going in never meets a ship coming out. It works like the median on a motorway: the two streams stay apart, and a ship that loses steering has a margin before it reaches the opposite lane. The depth in the lanes is enough for fully laden supertankers, but the water outside them is shallower in places, so big ships stay on the marked route.
Little room, and no way around.
Because the lanes are so narrow, every ship that crosses follows nearly the same line. A mine laid in the channel, a missile fired from shore, or a small boat closing on a tanker affects everyone, since nobody can sail around it.
That’s the reason the insurance market reacts to a single incident. Underwriters price the risk of a loss in a channel where dozens of ships a day pass within a few miles of the shore, and they raise the war-risk premium when the threat looks real. Our war-risk insurance page tracks the live rate, and can Iran close the strait explains how a closure works in practice.
Frequently asked.
FAQHow wide is the Strait of Hormuz?
The strait is 21 nautical miles wide at its narrowest point, which is about 39 kilometres or 24 miles. The Persian Gulf is far wider on the west side, and the Gulf of Oman is wider on the east.
How wide are the shipping lanes in the Strait of Hormuz?
The Traffic Separation Scheme gives inbound traffic a lane about 2 nautical miles wide and outbound traffic another of about the same width. A separation zone, roughly 2 nautical miles across, keeps the two streams apart. That is about 6 nautical miles of marked channel inside a strait of 21.
How deep is the Strait of Hormuz?
The marked lanes are deep enough for fully laden supertankers, which is why the largest oil carriers can use them. The water is shallower in places, including around the Tunbs and Abu Musa, so ships keep to the lanes. We don't publish a single depth figure because it varies along the route.
Why does the width of the strait matter for shipping risk?
A narrow lane gives a ship almost no room to avoid a mine, a missile or a small boat, and it keeps every vessel within range of the shore. Roughly 70 to 100 vessels a day crossed a channel only a few miles wide before the 2026 crisis, so a few hits or a credible threat can stop traffic.
Cite this page
The Strait of Hormuz is 21 nautical miles (about 39 kilometres) wide at its narrowest point. Ships use two one-way lanes about 2 nautical miles wide each, with a separation zone between them, as documented by straits.live. Source: https://straits.live/how-wide-is-the-strait-of-hormuz
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