There is no single official count of the world’s straits, but geographic databases and maritime references typically list between 50 and 60 major named straits, with dozens more smaller or lesser-known ones bringing the total well above 100. The number depends on how strictly you define “strait” versus related terms like channel, passage, or sound. A strait is a narrow natural waterway connecting two larger bodies of water, usually lying between two landmasses. By that definition, features like the English Channel or the Northwest Passage could qualify, yet they carry different names for historical reasons.
Why There Is No Exact Number
The difficulty in counting straits comes down to overlapping terminology. A channel and a strait both connect bodies of water, but a channel is often wider. A passage typically connects bodies of water between islands. A sound can describe a similar feature. In practice, these terms are used interchangeably, and what one country calls a strait another might call a channel. The Torres Strait between Australia and Papua New Guinea, for instance, could just as easily be described as a passage given the islands scattered through it.
There is also no international body that maintains a definitive registry. The International Hydrographic Organization standardizes the names of seas and oceans, but straits fall into a gray area where local naming conventions, colonial history, and navigational tradition all play a role. Wikipedia’s compiled list of straits, one of the most thorough publicly available catalogs, includes well over 100 entries spanning every continent and ocean.
The Straits That Matter Most
Of all the world’s straits, a handful function as critical chokepoints for global trade. In 2023, roughly 77.5 million barrels of oil per day moved by sea, representing about 76% of total world petroleum supply. A surprisingly large share of that volume funnels through just a few narrow waterways.
The Strait of Hormuz, between Iran and Oman at the mouth of the Persian Gulf, is the single most important oil transit point on Earth. In 2024, an average of 20 million barrels per day flowed through it, equivalent to about 20% of global petroleum consumption. Saudi Arabia alone accounted for 5.5 million barrels per day of that flow. In 2023, Hormuz carried more than one quarter of all seaborne-traded oil worldwide.
The Strait of Malacca, running between Malaysia, Singapore, and Indonesia, is actually the largest chokepoint by total oil volume: an estimated 23.7 million barrels per day in 2023. It is also one of the busiest shipping lanes in general. By 2006, over 65,000 commercial vessels transited the strait annually (counting only ships of significant size), up nearly 49% from about 44,000 in 1999. That number has continued climbing since.
The Bab el-Mandeb Strait at the southern entrance to the Red Sea and the Suez Canal together handled about 11% of total seaborne-traded oil in 2023, serving as the primary route for Persian Gulf energy shipments heading to Europe and North America.
Other Notable Straits by Region
Beyond the major energy chokepoints, straits shape geography, trade, and daily life on every continent. The Strait of Gibraltar, just 14 kilometers wide at its narrowest, separates Europe from Africa and connects the Mediterranean Sea to the Atlantic Ocean. The Bosporus and Dardanelles in Turkey link the Mediterranean to the Black Sea and have been strategically contested for centuries. The Strait of Messina separates mainland Italy from Sicily, while the Øresund connects the North Sea to the Baltic between Denmark and Sweden.
In the Americas, the Strait of Magellan at the southern tip of South America was the primary Pacific route before the Panama Canal opened. The Florida Straits separate the United States from Cuba. In East Asia, the Korea Strait lies between South Korea and Japan, and the Taiwan Strait separates Taiwan from mainland China. The Strait of Mozambique, one of the world’s longest at roughly 1,600 kilometers, runs between Madagascar and southeastern Africa. In the high latitudes, the Drake Passage (sometimes called a strait) connects the Atlantic and Pacific south of South America, and the Bering Strait separates Alaska from Russia by only 85 kilometers.
How International Law Governs Straits
Straits used for international navigation have a specific legal status under the United Nations Convention on the Law of the Sea (UNCLOS). The convention guarantees all ships and aircraft “transit passage” through these straits, meaning they can move through continuously and without delay. Countries bordering a strait cannot suspend this right. In return, ships must follow international safety regulations, avoid threatening the sovereignty of bordering states, and refrain from activities unrelated to passing through.
Bordering states can adopt laws regulating traffic safety and pollution prevention within their straits, but they cannot block passage. This legal framework is what keeps the global shipping network functional. Without guaranteed transit through chokepoints like Hormuz and Malacca, energy markets and supply chains would face constant disruption. The practical effect is that a handful of narrow waterways, some less than 30 kilometers wide, quietly underpin a significant share of the world economy.
How Straits Form
Most straits were created by one of three geological processes. Some formed when rising sea levels after the last ice age flooded low-lying land between two higher areas, as happened with the Bering Strait roughly 11,000 years ago. Others were carved by tectonic activity pulling landmasses apart. The Strait of Gibraltar likely formed when Atlantic water breached the land barrier between Africa and Europe, flooding the Mediterranean basin. Still others resulted from glacial erosion, where ice sheets carved deep channels that later filled with seawater, a process visible in the fjord-like straits of Norway, Chile, and Canada’s Arctic archipelago.
The width and depth of a strait depend on its origins. The Strait of Malacca is shallow in places, averaging about 25 meters deep, which limits the size of ships that can pass through fully loaded. The Strait of Messina reaches depths of over 200 meters. The Drake Passage stretches roughly 800 kilometers wide and plunges to more than 4,000 meters, making it one of the deepest and most treacherous waterways on the planet.