Seven continents, five oceans, and one planet whose pieces are still on the move.
Ask a class in Chicago how many continents there are and most hands will say seven. Ask a class in Mexico City or Madrid and many will say six. Neither class is wrong. On this page you'll find out why, meet every continent and ocean with real numbers, and see how scientists figured out that the continents used to be stuck together.
What Is a Continent?
A continent is one of Earth's seven main divisions of land. Most continents are huge landmasses, big connected pieces of land with ocean around most of their edges. Together they cover about 148 million square kilometers (57 million square miles), a little less than a third of Earth's surface.
A continent also includes the islands that sit on its continental shelf. That's the shallow, underwater edge of a continent before the seafloor drops away to the deep ocean. That's why Japan counts as part of Asia, and Greenland and the Caribbean islands count as part of North America.
Here's the catch: there's no single rule that every scientist and country agrees on. Continents are partly a matter of physical geography (land and water) and partly a matter of history and custom. Europe and Asia are the best example. They sit on one connected landmass, sometimes called Eurasia. The line between them is imaginary. By custom it runs down the Ural Mountains, along the Ural River and the Caspian Sea, and through the Caucasus Mountains to the Black Sea.
Seven, Six or Five?
How many continents you learn about depends a lot on where you go to school. Here are the most common ways to count:
7 continents
Africa, Antarctica, Asia, Australia, Europe, North America and South America. This is the list most students in the United States learn, and it's the one this course uses.
6 continents (one America)
North and South America are joined into one continent, America. Most students in Latin America and Europe learn it this way. The two Americas are connected by land, and they have only been joined for about 3 million years.
6 continents (Eurasia)
Europe and Asia are joined as Eurasia, since no ocean separates them. Some geologists see it this way, because the two share one landmass.
5 continents
The five Olympic rings stand for "the union of the five continents." Five-continent lists usually join the Americas into one and leave out Antarctica, where nobody lives permanently.
Some lists also say Oceania instead of Australia. Oceania means Australia plus the islands of the Pacific, like New Zealand and Fiji. In this lesson, "Australia" the continent means the country of Australia, the eastern part of the island of New Guinea, and New Zealand, which is how National Geographic draws it.
Map of the Continents and Oceans
All seven continents and five oceans. The dashed line on land is the usual Europe–Asia boundary. The dashed line at 60°S marks the northern edge of the Southern Ocean. The island of New Guinea is split between two colors: its western half belongs to Indonesia and is counted with Asia, and its eastern half belongs to Papua New Guinea and is counted with Australia. On a phone the map comes in two halves: west, then east.
Notice how the oceans all run into each other. There are no walls in the water. That's why oceanographers talk about one big world ocean, which covers about 71 percent of Earth. We divide it into five named oceans to make it easier to talk about.
The Seven Continents, One by One
Here they are from largest to smallest. Population figures are estimates for 2023 from the United Nations, as published by Our World in Data. Their regions don't match continents perfectly (for example, all of Russia is counted in Europe), so treat them as close, not exact.
Asia
Area
About 44.6 million km² (17.2 million sq mi), the largest
People (2023)
About 4.8 billion, roughly 6 in every 10 people on Earth
Highest point
Mount Everest, 8,849 m (29,032 ft), on the border of Nepal and China
Longest river
Yangtze, about 6,300 km (3,915 mi)
Did you know? The shore of the Dead Sea, in Southwest Asia, is more than 390 meters (1,280 feet) below sea level. It's the lowest dry land on Earth.
Sources: Britannica; UN via Our World in Data; National Geographic
Africa
Area
About 30.4 million km² (11.7 million sq mi)
People (2023)
About 1.5 billion
Highest point
Kilimanjaro, 5,895 m (19,341 ft), in Tanzania
Longest river
Nile, about 6,650 km (4,132 mi), the longest river in the world by most measurements
Did you know? Africa is the only continent crossed by both the Equator and the Prime Meridian. They meet at 0°, 0° in the Atlantic Ocean, just off its west coast. Check it on the map above.
Sources: Britannica; UN via Our World in Data; UNESCO
North America
Area
About 24.2 million km² (9.4 million sq mi)
People (2023)
About 609 million, counting Central America and the Caribbean
Highest point
Denali, 6,190 m (20,310 ft), in Alaska
Longest river
Missouri, about 4,090 km (2,540 mi). It flows into the Mississippi River, which is about 3,770 km (2,340 mi) long.
Did you know? Greenland, the largest island in the world, is part of North America. So are the islands of the Caribbean. Politically, Hawaii is part of the U.S., but geographers usually place it in Oceania.
Sources: Britannica; UN via Our World in Data; USGS; National Geographic
South America
Area
About 17.8 million km² (6.9 million sq mi)
People (2023)
About 433 million
Highest point
Aconcagua, 6,959 m (22,831 ft), in Argentina, the highest mountain in the Americas
Longest river
Amazon, at least 6,400 km (4,000 mi). It carries more water than the next six largest rivers combined.
Did you know? Angel Falls in Venezuela is the world's tallest waterfall. Its water drops 979 meters (3,212 feet).
Sources: Britannica; UN via Our World in Data; National Geographic
Antarctica
Area
About 14.2 million km² (5.5 million sq mi)
People (2023)
No permanent residents. Scientists and support staff live at research stations for months at a time.
Highest point
Vinson Massif, 4,892 m (16,050 ft)
Longest river
None that flow all year. The Onyx River, a meltwater stream about 30 km (20 mi) long, flows only in summer.
Did you know? Antarctica is the coldest, driest and windiest continent. On July 21, 1983, Vostok Station recorded −89.2 °C (−128.6 °F). Its ice sheet holds about 90 percent of all the ice on Earth.
Sources: Britannica; USGS; PolarTREC
Europe
Area
About 10 million km² (about 4 million sq mi)
People (2023)
About 747 million, counting all of Russia
Highest point
Mount Elbrus, 5,642 m (18,510 ft), in Russia, if the Caucasus Mountains count as Europe. If not, Mont Blanc, about 4,807 m (15,771 ft), on the border of France and Italy.
Longest river
Volga, about 3,530 km (2,193 mi), in Russia
Did you know? Europe is the second-smallest continent. It's only slightly larger than the country of Canada.
Sources: Britannica; UN via Our World in Data; National Geographic
Australia
Area
Just under 8.5 million km² (about 3.3 million sq mi), the smallest. The country of Australia alone is about 7.7 million km².
People (2023)
About 46 million in all of Oceania, which includes Australia, New Zealand, Papua New Guinea and the Pacific islands
Highest point
Mount Kosciuszko, 2,228 m (7,310 ft), on the Australian mainland
Longest river
Murray, about 2,508 km (1,558 mi)
Did you know? Australia is the flattest continent and the second-driest, after Antarctica. Koalas, platypuses and Tasmanian devils developed there in isolation, and the Great Barrier Reef off its northeast coast is the world's largest coral reef ecosystem.
Sources: National Geographic; Geoscience Australia; UN via Our World in Data
Why the "if" for Europe and Australia? Europe's highest point depends on where you draw the Europe–Asia line. If the Caucasus Mountains count as Europe, it's Mount Elbrus. If not, it's Mont Blanc. Australia's depends on whether you count all of New Guinea. Puncak Jaya, at 4,884 meters (16,024 feet), is on the western, Indonesian side of the island, which this lesson counts with Asia. That's why the card shows Mount Kosciuszko, the highest point on the Australian mainland.
The Five Oceans
An ocean is one of the big named parts of the world ocean. Here are all five, from largest to smallest. Notice how the Pacific alone covers more area than all the land on Earth put together.
The five oceans by area (NOAA National Centers for Environmental Information)
Ocean
Area
Share of the world ocean
Deepest measured spot
Pacific
161.8 million km²
44.7%
10,803 m
Atlantic
85.1 million km²
23.5%
8,486 m
Indian
70.6 million km²
19.5%
7,906 m
Southern
22.0 million km²
6.1%
7,075 m
Arctic
15.6 million km²
4.3%
5,567 m
Depths are from one global data set. Other surveys of the deepest trenches get slightly different numbers, because measuring the bottom of a trench 10 kilometers down is hard.
The newest ocean on the map
For most of the 1900s, many maps showed only four oceans. The water around Antarctica was split up among the Pacific, Atlantic and Indian Oceans. But scientists noticed that this water is different. A strong current, the Antarctic Circumpolar Current, flows all the way around Antarctica from west to east. It formed about 34 million years ago and carries more water than any other ocean current. It keeps the water inside it colder and a bit less salty than the water to the north.
So the Southern Ocean got its own name. It runs from the coast of Antarctica out to 60 degrees south latitude. Here's how it made its way onto maps:
1937: The International Hydrographic Organization (IHO), a group of countries that works on standard names for the seas, listed a Southern Ocean. In 1953 it dropped the name again.
1999: The U.S. Board on Geographic Names started using the name Southern Ocean.
2000: Boundaries for the Southern Ocean were proposed to the IHO. Its member countries never ratified them, so there's still no worldwide agreement.
February 2021: NOAA, the U.S. ocean and weather agency, recognized the Southern Ocean.
June 8, 2021: National Geographic began labeling it on its maps, on World Oceans Day. Since it started making maps in 1915, it had recognized four.
Plates and Pangaea
Earth's outer shell isn't one solid piece. It's cracked into giant slabs called tectonic plates. The continents and ocean floors ride on top of these plates, which move very slowly, usually a few centimeters a year. The study of how plates move is called plate tectonics.
A few centimeters a year doesn't sound like much. But over millions of years it adds up to thousands of kilometers. More than 250 million years ago, almost all of Earth's land was joined into one supercontinent called Pangaea, a name that means "all lands." About 200 million years ago Pangaea began to break apart, and its pieces slowly drifted to where the continents are today. They're still moving. The Atlantic Ocean, for example, is getting wider by about 2.5 centimeters a year.
How Do We Know? Clues That the Continents Move
In 1912, a 31-year-old German scientist named Alfred Wegener made a bold claim: the continents had once been joined and had drifted apart. He called his idea continental drift and laid it out in a 1915 book, The Origin of Continents and Oceans. Here's the evidence he and later scientists used.
1. The coastlines fit
Look at a map and you'll notice that the bulge of eastern South America seems to tuck into the curve of western Africa. The mapmaker Abraham Ortelius pointed it out as early as 1596. Wegener took it seriously.
Turn South America clockwise and slide it east, and the bulge of Brazil tucks into the Gulf of Guinea, the corner of West Africa. The two Mesosaurus areas meet. This is a simplified sketch drawn from coastlines, so a thin gap is left between them. Scientists who fit the real edges of the continental shelves, which lie underwater, get an even closer match.
2. The same fossils on different continents
Mesosaurus was a small reptile that lived in fresh water about 300 million years ago. Its fossils turn up in both southern Africa and South America. A freshwater reptile couldn't have swum across the salty Atlantic, so the two lands were probably joined. Fossils of a fern-like plant called Glossopteris show up in South America, Africa, India, Australia and even Antarctica. Today Antarctica is far too cold for plants like that. Together these continents once made up the southern part of Pangaea.
3. Matching rocks
Rock layers along the coasts of South America and Africa match each other, as if a single rock formation had been torn in two.
4. The missing piece: seafloor spreading
Most scientists rejected Wegener's idea for decades. The problem was that he couldn't explain what force could push whole continents around. He died in 1930 on an expedition across the Greenland ice cap, long before he was proved right.
The answer came from the bottom of the ocean. Starting in the 1950s, the geologist and mapmaker Marie Tharp turned depth measurements from ships into detailed maps of the seafloor, including the Mid-Atlantic Ridge, an underwater mountain range that runs down the middle of the Atlantic. Around the same time, ships towing instruments that sense magnetism found stripes in the seafloor rock. The pattern of stripes on one side of a ridge matched the pattern on the other side, like a mirror image. In the early 1960s, Harry Hess and Robert Dietz proposed seafloor spreading: hot rock rises at the ridges, forms new ocean floor, and pushes the older floor (and the continents) apart. In 1968 the drilling ship Glomar Challenger brought up seafloor rock cores that confirmed it: the rock gets older the farther it is from the ridge.
Game: Which Continent Am I?
Each round, a mystery continent describes itself one clue at a time. Guess from the first clue for 3 points. If you need another clue, it's worth 2, and then 1. A wrong guess costs you a clue. There are 7 rounds, one for every continent, so a perfect game is 21.
Pick a continent with the buttons below, or press the number keys 1 to 7. Use Tab to move between buttons and Enter to press one.
Get ready…
Round 1 of 7 · Score 0 · Best 0
How scoring works
A right answer earns 3 points if you've seen one clue, 2 points after two clues, and 1 point after three. Each wrong guess shows the next clue for you. If you miss after the third clue, the round is worth 0 and the answer is shown. Your best score is saved only in this browser.
Quiz: Continents and Oceans
Ten questions. Choose one answer for each, then check your score. You can try as many times as you like.
Talk About It
Should Europe and Asia count as two continents or one? Make the best case for the side you don't agree with.
Nobody lives in Antarctica permanently. Should it still count as a continent? Why do you think the five-continent list leaves it out?
Wegener had good evidence, but most scientists rejected his idea for about 50 years. Is it a good thing or a bad thing that scientists wanted proof of how the continents moved before they believed it?
The Southern Ocean was on some maps, then off, then back on. Who do you think should get to decide what goes on a map?
Sources
National Geographic Education, Continent (what a continent is, islands and continental shelves, Eurasia, the continent of Australia, Europe compared with Canada, the Dead Sea, Angel Falls, the Amazon, Australian wildlife and the Great Barrier Reef).
National Geographic Education, Continental Drift (Mesosaurus, matching rocks and fossils, Marie Tharp, Pangaea).
Credits
Written by Marco for Jugami's World Geography course. All maps and diagrams are original SVG drawings made for this page. The coastlines are simplified by hand from latitude and longitude points, so small islands are left out and shapes are approximate. The puzzle-fit sketch uses more detailed hand-traced outlines of South America and Africa. A computer turned South America on the globe to line up coast points that once sat side by side, then drew both on a flat projection. The Mesosaurus areas on it are approximate.
