How big is Lake Superior?

Lake Superior is so vast that it can feel more like an inland sea than a lake. Stretching across the border between the United States and Canada, it is the largest freshwater lake in the world by surface area, covering approximately 31,700 square miles (82,100 square kilometers).

But surface area tells only part of the story. Lake Superior stretches about 350 miles (563 kilometers) from west to east, reaches up to 160 miles (258 kilometers) across, and holds an extraordinary volume of water. Its immense size, remarkable depth, and long shoreline make it not only the largest of North America’s Great Lakes by surface area, but also one of the most impressive bodies of freshwater on Earth.

So, just how big is Lake Superior? This article takes a closer look at its surface area, length, width, depth, water volume, shoreline, and how its size compares with other Great Lakes, U.S. states, and countries.

Lake Superior Size at a Glance

Lake Superior is enormous by any measure. Its vast surface area, impressive length and width, exceptional depth, and enormous water volume make it one of the most remarkable freshwater bodies on Earth. The table below provides a quick overview of just how large Lake Superior is.

Measurement	Size
Surface Area	31,700 sq mi (82,100 sq km)
Length	350 miles (563 km)
Maximum Width	160 miles (258 km)
Water Volume	About 2,900 cubic miles (12,100 cubic km)
Maximum Depth	1,332 feet (406 m)
Average Depth	483 feet (147 m)
Shoreline Length	2,726 miles (4,385 km)

These numbers help explain why Lake Superior is often described as having the scale and presence of an inland sea. Looking across parts of the lake, the opposite shore may be far beyond the horizon, while its enormous depth and volume make its overall scale even more remarkable than its surface area alone suggests.

How Large Is Lake Superior by Surface Area?

Lake Superior covers approximately 31,700 square miles (82,100 square kilometers), making it the largest freshwater lake in the world by surface area. Its size alone sets it apart from nearly every other freshwater lake on Earth and makes it the largest of North America’s five Great Lakes.

To put that into perspective, Lake Superior’s surface is so vast that standing on one shore often provides no view of the opposite side. Across much of the lake, the distance between shorelines is far beyond what the human eye can see, creating a horizon that can look remarkably similar to the open ocean.

Lake Superior’s enormous surface area is also responsible for many of the characteristics that make the lake unique. Its vast expanse helps generate powerful waves and intense storms, influences local weather along its shores, and contributes to the lake’s reputation as one of the most dramatic and powerful freshwater environments in North America.

While several lakes around the world contain more water or reach greater depths, no freshwater lake covers a larger surface area than Lake Superior.

How Long and Wide Is Lake Superior?

Lake Superior is not only vast in surface area but also remarkable in its physical dimensions. The lake stretches approximately 350 miles (563 kilometers) from west to east, making it longer than many people expect when they think of a freshwater lake.

At its widest point, Lake Superior measures about 160 miles (258 kilometers) from north to south. These dimensions give the lake an enormous open-water expanse, with some areas extending so far that land on the opposite shore is completely beyond the horizon.

Traveling across Lake Superior can therefore involve distances more commonly associated with coastal waters than inland lakes. Its exceptional length and width are a major reason why the lake has such a powerful influence on weather, waves, and conditions along its shores.

Together, its 350-mile length and maximum width of 160 miles help illustrate the extraordinary scale behind Lake Superior’s reputation as one of the largest and most impressive freshwater bodies on Earth.

How Deep Is Lake Superior?

Lake Superior is not only the largest freshwater lake in the world by surface area—it is also exceptionally deep. Its maximum depth is approximately 1,332 feet (406 meters), while its average depth is about 483 feet (147 meters).

The lake’s enormous depth is one of the main reasons it holds such an extraordinary amount of freshwater. Deep basins beneath the surface allow Lake Superior to contain far more water than its already impressive surface area might suggest.

Its depth also plays an important role in shaping the lake’s character. The enormous volume of deep water changes temperature slowly, helping keep Lake Superior famously cold for much of the year. Even during summer, water temperatures in deeper parts of the lake remain extremely cold.

Combined with its vast surface area, Lake Superior’s depth gives it a scale that few freshwater lakes can match. Although some lakes elsewhere in the world are deeper, Lake Superior’s combination of exceptional depth and enormous surface area makes it one of the most massive freshwater bodies on Earth.

How Large Is Lake Superior’s Shoreline?

Lake Superior has an enormous shoreline stretching approximately 2,726 miles (4,385 km). This includes the lake’s extensive coastline along both the United States and Canada, as well as the many bays and inlets that shape its irregular shoreline.

The length of the shoreline adds another dimension to Lake Superior’s immense size. If its shoreline were stretched out as a single route, it would cover a distance comparable to traveling across a large portion of the United States.

The shoreline also varies considerably around the lake. Some areas feature rugged rocky cliffs and exposed bedrock, while others contain sandy beaches, sheltered bays, forests, and wetlands. This diverse coastline is a reflection of the lake’s enormous geographic extent.

With approximately 2,726 miles of shoreline, Lake Superior has a coastline long enough to make the lake feel less like an enclosed inland water body and more like a vast inland sea.

Lake Superior Shoreline Compared With Other Great Lakes

Great Lake	Shoreline Length	Compared With Lake Superior
Lake Huron	3,827 mi (6,159 km)	About 140%
Lake Superior	2,726 miles (4,385 km)	100%
Lake Michigan	1,640 mi (2,639 km)	About 60%
Lake Erie	871 mi (1,402 km)	About 32%
Lake Ontario	712 mi (1,146 km)	About 26%

How Much Water Does Lake Superior Hold?

Lake Superior holds an extraordinary amount of freshwater. The lake contains approximately 2,900 cubic miles (12,100 cubic kilometers) of water, equivalent to roughly 3 quadrillion gallons.

This immense volume is what makes Lake Superior especially remarkable. Its enormous surface area is impressive on its own, but the lake’s great depth allows it to store an exceptional quantity of water beneath that vast surface.

Lake Superior contains more water than any other Great Lake by volume. Its water volume is also so immense that it accounts for a significant share of the freshwater contained in the entire Great Lakes system.

Together, Lake Superior’s vast surface area and exceptional depth create one of the largest concentrations of freshwater on Earth, giving the lake a scale that is difficult to fully appreciate without comparing it with other Great Lakes and large geographic areas.

How Does Lake Superior Compare to the Other Great Lakes?

Lake Superior is the largest of North America’s five Great Lakes by surface area and also contains the greatest volume of water. Its approximately 31,700 square miles (82,100 square kilometers) of surface area make it significantly larger than Lake Huron, Lake Michigan, Lake Erie, and Lake Ontario.

Its enormous water volume is equally impressive. Lake Superior holds about 2,900 cubic miles (12,100 cubic kilometers) of water, giving it a greater volume than any of the other Great Lakes individually. Its exceptional depth, including a maximum depth of 1,332 feet (406 meters), allows it to store an extraordinary amount of freshwater beneath its vast surface.

Lake Superior is therefore the dominant Great Lake in terms of overall scale. While the other Great Lakes are also enormous bodies of freshwater, none combines such a vast surface area, exceptional depth, and immense water volume.

This combination is one of the main reasons Lake Superior is widely considered the most physically imposing of the Great Lakes and why it is often described as feeling more like an inland sea than a typical lake.

Lake Superior vs. Other Great Lakes

Great Lake	Surface Area	Maximum Depth	Water Volume
Lake Superior	31,700 sq mi (82,100 sq km)	1,332 ft (406 m)	2,900 cu mi (12,100 cu km)
Lake Michigan	22,400 sq mi (58,000 sq km)	923 ft (281 m)	1,180 cu mi (4,920 cu km)
Lake Huron	23,000 sq mi (59,600 sq km)	750 ft (229 m)	850 cu mi (3,540 cu km)
Lake Erie	9,910 sq mi (25,700 sq km)	210 ft (64 m)	116 cu mi (484 cu km)
Lake Ontario	7,340 sq mi (19,000 sq km)	802 ft (244 m)	393 cu mi (1,640 cu km)

Figures are approximate.

The table shows just how dominant Lake Superior is among the Great Lakes. It has the largest surface area, greatest maximum depth, and largest water volume of all five lakes. Its surface area is roughly one-third larger than Lake Michigan or Lake Huron, while its water volume is more than twice that of either lake.

How Big Is Lake Superior Compared With Other Large Lakes?

Lake Superior ranks among the world’s largest lakes by surface area, but its size becomes even more impressive when compared with other famous large lakes. Its 31,700-square-mile (82,100-square-kilometer) surface area is substantially greater than that of Lake Victoria, Lake Huron, Lake Michigan, and Lake Tanganyika.

Among freshwater lakes, Lake Superior is the largest by surface area. Its enormous dimensions are especially notable because it is much larger than many other globally recognized lakes that are themselves considered exceptionally large.

Lake	Surface Area	Comparison With Lake Superior
Lake Superior	31,700 sq mi (82,100 sq km)	—
Lake Victoria	26,600 sq mi (68,800 sq km)	Superior is larger
Lake Huron	23,000 sq mi (59,600 sq km)	Superior is larger
Lake Michigan	22,400 sq mi (58,000 sq km)	Superior is larger
Lake Tanganyika	12,700 sq mi (32,900 sq km)	Superior is much larger

Surface areas are approximate.

This comparison highlights the extraordinary scale of Lake Superior. Even when placed alongside some of the world’s most famous large lakes, its broad surface area remains exceptional.

How Big Is Lake Superior Compared With U.S. States?

At 31,700 square miles (82,100 square kilometers), Lake Superior is larger in area than several U.S. states. Its surface area is especially striking when compared with smaller states, giving a better sense of how enormous the lake really is.

Lake Superior is roughly comparable in size to South Carolina, while it is larger than West Virginia, Maryland, Hawaii, Massachusetts, Vermont, and New Hampshire by surface area. It is also somewhat smaller than Maine.

This comparison shows that Lake Superior is not simply a large lake—it covers an area comparable to the size of an entire U.S. state. Its 31,700-square-mile surface would stretch across a substantial portion of the northeastern United States if it were placed on land.

U.S. State	Approx. Area	How It Compares With Lake Superior
Maine	35,380 sq mi	Slightly larger
South Carolina	32,020 sq mi	Slightly larger
Lake Superior	31,700 sq mi	—
West Virginia	24,038 sq mi	Lake Superior is larger
Maryland	12,407 sq mi	Lake Superior is much larger
Hawaii	10,932 sq mi	Lake Superior is much larger
Massachusetts	10,554 sq mi	Lake Superior is much larger
Vermont	9,616 sq mi	Lake Superior is much larger
New Hampshire	9,349 sq mi	Lake Superior is much larger

Areas are approximate and refer to total state area; comparisons are intended to illustrate the scale of Lake Superior.

How Big Is Lake Superior Compared With Countries?

Lake Superior is comparable in size to several European countries, making its enormous surface area easier to understand from a geographic perspective. With approximately 31,700 square miles (82,100 square kilometers) of surface area, Lake Superior is slightly smaller than Austria but slightly larger than the Czech Republic. It is also considerably larger than Republic of Ireland, Latvia, Croatia, Switzerland, and Belgium.

These comparisons show that Lake Superior is not merely a large lake—it has a surface area comparable to that of an entire European country. The table below compares Lake Superior with several countries of similar or smaller size.

Place	Type	Surface Area (sq mi)	Surface Area (sq km)	Compared With Lake Superior
Austria	Country	32,386	83,879	2.2% larger
Lake Superior	Lake	31,700	82,100	100%
Czech Republic	Country	30,450	78,866	3.9% smaller
Republic of Ireland	Country	27,133	70,273	14.4% smaller
Latvia	Country	24,938	64,589	21.3% smaller
Croatia	Country	21,851	56,594	31.1% smaller
Switzerland	Country	15,940	41,285	49.7% smaller
Belgium	Country	11,787	30,528	62.8% smaller

Can Lake Superior Hold All the Water in the Other Great Lakes?

Lake Superior is so large that its water volume is greater than that of any other individual Great Lake. It contains approximately 2,900 cubic miles (12,100 cubic kilometers) of water, far more than Lake Michigan, Lake Huron, Lake Erie, or Lake Ontario individually.

Its enormous capacity comes from the combination of a vast surface area and exceptional depth. With a maximum depth of 1,332 feet (406 meters) and an average depth of about 483 feet (147 meters), Lake Superior stores an extraordinary amount of freshwater beneath its surface.

When the five Great Lakes are considered together, however, the picture is different. The combined volume of all five lakes is substantially greater than Lake Superior alone. Lake Superior nevertheless accounts for a remarkable share of the freshwater stored within the Great Lakes system.

This is one of the clearest ways to understand why Lake Superior stands apart from the other Great Lakes: it is not simply the largest by surface area—it is also the deepest and holds the greatest volume of water.

Great Lakes by Water Volume

Great Lake	Water Volume	Compared With Lake Superior
Lake Superior	2,900 cu mi (12,100 cu km)	—
Lake Michigan	1,180 cu mi (4,920 cu km)	About 41% of Superior
Lake Huron	850 cu mi (3,540 cu km)	About 29% of Superior
Lake Ontario	393 cu mi (1,640 cu km)	About 14% of Superior
Lake Erie	116 cu mi (484 cu km)	About 4% of Superior

Water volumes are approximate.

Lake Superior’s approximately 2,900 cubic miles of water is more than twice the volume of Lake Michigan, more than three times that of Lake Huron, and more than seven times that of Lake Ontario. Compared with Lake Erie, Lake Superior holds roughly 25 times as much water.

This comparison makes clear that Lake Superior’s enormous size is not simply a result of its broad surface. Its great depth allows it to store an extraordinary volume of freshwater as well.

Why Does Lake Superior Feel So Vast?

Lake Superior feels much larger than a typical lake because of the sheer combination of its surface area, length, width, and depth. Its 31,700-square-mile surface stretches hundreds of miles across, creating enormous areas of open water with little or no land visible on the horizon.

On calm days, the lake can resemble an inland sea, while strong winds can produce large waves and rapidly changing conditions. The opposite shoreline may be too distant to see, making it difficult to judge the lake’s true size simply by looking across it.

Its depth adds another dimension to its scale. With an average depth of about 483 feet (147 meters) and a maximum depth of 1,332 feet (406 meters), a tremendous amount of freshwater lies beneath the surface.

The combination of a huge surface, great distances between shores, and exceptional depth is what gives Lake Superior its distinctive inland-sea character. Its size is not defined by one measurement alone; it is the result of several extraordinary dimensions coming together in a single freshwater lake.

Frequently Asked Questions About the Size of Lake Superior