Largest Lake in the World
& Largest Lake in the United States
Caspian Sea map: Map of the Caspian Sea - World's largest landlocked water body (by surface area). Image by CIA.
Which Lake is the World's Largest?
There are a few different ways to define the world's largest lake. Are you interested in the lake with the largest surface area? Or, the lake with the greatest water volume? And, do you want to consider saltwater seas in your comparison?
"Which lake is the world's largest?" is not a simple question to answer. So, we will explore the question from a few different perspectives.
World's Largest Lake (by volume):
Lake Baikal is the world's largest freshwater lake in terms of volume. It contains about 5,521 cubic miles of water (23,013 cubic kilometers), or approximately 20% of Earth's fresh surface water. This is a volume of water approximately equivalent to all five of the North American Great Lakes combined.
While Lake Baikal is extremely deep, its surface area is only about 12,248 square miles (31,722 square kilometers), putting it in seventh place worldwide in terms of surface area.
Related: World's Deepest Lake
Lake Baikal map: Map of Lake Baikal - World's largest freshwater lake (by volume). Image by CIA.
World's Largest Lake (by surface area):
The salty Caspian Sea has the greatest surface area of any lake at 143,200 square miles (370,886 square kilometers).
Lake Superior, on the United States/Canada border, is the named freshwater lake with the greatest surface area at 31,700 square miles (82,103 square kilometers).
However, Lake Michigan and Lake Huron can technically be considered a single lake because they both have the same surface elevation and they are connected by the Mackinac Strait (which is not a river because the water does not have a consistent flow direction). So, Lake Michigan-Huron could be considered the largest freshwater lake in the world by surface area. It has a total surface area of 45,410 square miles (117,611 square kilometers), which is significantly larger than Lake Superior. The total water volume in Lake Michigan-Huron, at 2,026 cubic miles (8,443 cubic kilometers), is much smaller than the volume of Lake Baikal.
Great Lakes map: Map of Lake Superior and Lake Michigan-Huron - World's largest freshwater lakes (by surface area). Image by CIA.
Largest Lake in the United States (by volume):
The largest lake in the United States on the basis of water volume is Lake Superior with a volume of 2,904 cubic miles (12,104 cubic kilometers).
Largest Lake in the United States (by surface area):
Lake Superior is the single named lake with the largest surface area in the United States at 31,700 square miles (82,103 square kilometers).
However, as mentioned above, if you consider Lake Michigan and Lake Huron as a single lake, then Lake Michigan-Huron has the largest surface area at 45,410 square miles (117,611 square kilometers).