Largest Lakes in the World

Data

Source: Wikipedia — List of largest lakes.

Note: What You Should Know About the World's Largest Lakes

Size isn't everything — but it is a great place to start

When people talk about the "biggest" lake, they almost always mean surface area. That's what the chart and table above measure, so when we say the Caspian Sea "wins," we mean it sprawls across more square kilometres than any other lake on the planet. It's helpful to keep in mind, though, that "largest" can also mean deepest or greatest volume — and the winner changes depending on how you measure it. That kind of nuance is exactly why geographers like to be precise about their words.

The Caspian Sea — a lake that acts like a sea

The Caspian Sea tops the list at about 371,000 km² — nearly four and a half times bigger than Lake Superior, which comes in second. It's often classed as a sea because it's enormous, salty, and sits in an enclosed basin that was once connected to the world's oceans. Technically, though, it's an endorheic lake: it has no natural outlet, and water leaves mainly through evaporation. Bordering five countries (Azerbaijan, Iran, Kazakhstan, Russia and Turkmenistan), it's both a geographic giant and a politically important one, with oil and gas reserves beneath its waters.

Freshwater champs: the Great Lakes

If you set aside the salty Caspian and rank only freshwater lakes, the story changes completely. Lake Superior becomes the largest freshwater lake in the world by surface area, and it's joined by its Great Lakes neighbours: Huron (3rd overall), Michigan (5th), and nearby Ontario and Erie that fall just outside this top-10 list. Together the Great Lakes hold about one-fifth of the world's fresh surface water and straddle the border of Canada and the United States. Fun detail: Lake Michigan and Lake Huron are connected by the wide Straits of Mackinac and are sometimes treated hydrologically as a single body of water.

Africa's great rift lakes

Africa is very well represented in the top ten, and most of its giants sit inside the East African Rift. Lake Victoria (3rd overall, about 69,485 km²) is the largest African lake and the source of the Nile; though it's shallow by continental standards, it's so broad it feels like an inland sea. Lake Tanganyika (6th) is different — it's narrow but extraordinarily deep, holding a huge share of the world's fresh water by volume and home to hundreds of fish species found nowhere else. Lake Malawi (9th), another rift lake, is similarly famed for its incredible array of endemic cichlid fish.

Deep and cold: the Siberian and Canadian giants

Lake Baikal (7th, about 31,722 km²) in Siberia earns its fame differently: it is the deepest lake on Earth, dropping over 1,600 metres to the bottom, and it holds roughly one-fifth of all the planet's fresh surface water — more by volume than all the North American Great Lakes combined. Great Bear Lake and Great Slave Lake, both in Canada's Northwest Territories, round out the top ten. They're among the largest lakes wholly inside one country, formed by glaciers and delightfully named ("great bear" before "bear" — Canadian honesty at its best).

Freshwater vs. saltwater

• Freshwater lakes (like Superior, Victoria, Huron, Michigan and Baikal) drain into rivers and oceans, keeping their salt content low.
• Saltwater lakes (like the Caspian Sea) sit in closed basins with no outlet; as water evaporates, dissolved minerals concentrate and make them salty.
• Some are even saltier than the ocean — the Dead Sea and the Great Salt Lake are classic examples, though they're much smaller than anything on this list.
• Whether a lake is "fresh" or "salty" shapes which plants and animals can survive, how it freezes, and whether it's good to drink from.

A few things worth knowing

• Largest by area: The Caspian Sea (~371,000 km²), even though it's often called a sea.
• Largest freshwater by area: Lake Superior (~82,100 km²).
• Deepest lake: Lake Baikal, more than 1,600 m — also the oldest, at around 25 million years.
• Largest by volume: Lake Baikal, holding roughly one-fifth of the world's fresh surface water.
• Largest African lake: Lake Victoria, and the source of the White Nile.
• Lakes cover only a small slice of the globe — around 3% of Earth's land surface (most of it is in the Northern Hemisphere).
• The Great Lakes hold roughly one-fifth of the world's fresh surface water between them.
• Most of the world's big lakes lie in formerly glaciated, cold northern regions.

Fun facts

• Lake Superior could hold all the water in the other four Great Lakes combined — and still leave room.
• Despite its name and saltiness, the Caspian Sea is home to seals — the Caspian seal is found nowhere else on Earth.
• Lake Baikal holds more water than the entire Great Lakes system, in a single lake.
• Lake Malawi has more species of fish than any other lake — over 1,000, almost all found only there.
• Because the Caspian's shoreline sits far below sea level, its surface is one of the lowest points on the planet.