How long is the Mekong? The river of six Asian countries
The Mekong is about 4,350 km (2,700 miles) long, and some sources give up to 4,900 km. It is the twelfth longest river in the world and flows through or along the borders of six countries, from the Tibetan Plateau to the South China Sea.
Lay the Mekong over your country
The river and a country at one scale. Pick a country, drag the river or switch the globe to the Mercator map.
Mekong: about 4,350 km (2,700 miles), about 1.1 times the straight-line distance from New York to Los Angeles (about 3,940 km).
Drag the river with your finger or mouse. It moves over the globe without changing shape or length, and its north stays up. The globe keeps the true proportions; on the Mercator map you can see how a river moved north grows.
Where the Mekong flows
The Mekong begins on the Tibetan Plateau in China, where it is called the Lancang. It then crosses Yunnan province, forms the border of Myanmar with Laos and of Laos with Thailand, crosses Cambodia and ends in a wide delta in Vietnam on the South China Sea.
The Mekong basin covers about 774,000 km². At its mouth the river carries about 17,000 m³/s of water on average. In the rainy season the swollen Mekong pushes water back up the Tonle Sap River into the lake of the same name in Cambodia.
Rivers of similar length, straightened
Rivers drawn at one scale. Straighten them to compare their lengths and see how they look on a Mercator map.
On a Mercator map: about 4,700 km
On a Mercator map the Mekong looks about 4,700 km long (×1.07 its true length). Its course lies close to the equator, so the map barely stretches it.
Open the Mercator mapHow long is it really?
About 4,350 km is the length given in the Encyclopædia Britannica table. Some sources give more, up to about 4,900 km, because they name a different source in the mountains of Tibet. For that reason we do not settle whether the Mekong is longer than the Congo, which is about 4,700 km.
The line on this page's maps is about 4,005 km long, shorter than the sources say, because a 1:10 million map smooths the bends and the mouth. That is why lengths here come from the sources, not from the drawing.
Mekong: questions and answers
The Mekong is about 4,350 km (2,700 miles) long according to Encyclopædia Britannica. Some sources give up to about 4,900 km.
The Mekong begins on the Tibetan Plateau in China. In its upper course it is called the Lancang.
The Mekong flows into the South China Sea through a wide delta in southern Vietnam.
China, Laos, Cambodia and Vietnam, and along the borders of Myanmar with Laos and of Laos with Thailand. That makes six countries.
According to Britannica it is not: the Mekong is about 4,350 km and the Congo about 4,700 km. Some sources, however, give the Mekong up to about 4,900 km, more than the Congo. The dispute is about the position of the source.