How big is Mount Everest?

Mount Everest is the highest mountain on Earth above sea level. Its summit stands 8,849 meters (29,032 feet) above sea level, a height China and Nepal announced together in 2020. The mountain rises in the Himalayas, on the border between Nepal and China.

Size

The official height, 8,848.86 meters, is measured to the surface of the snow on the summit. Survey teams from Nepal and China worked on it for more than a year and announced the result on December 8, 2020. They used satellite positioning at the top, and ground-penetrating radar to measure how deep the snow was. Nepal's survey department said the figure is accurate to within centimeters.

The rock beneath the snow is a little lower. In 2005, a Chinese survey put the rock height at 8,844.43 meters, and the two countries disagreed over which height to use. Before 2020, the widely accepted figure was 8,848 meters, measured by the Survey of India in 1954. A new survey was also wanted because some geologists thought a 2015 earthquake might have changed the height.

The Survey of India observed the peak between 1849 and 1855 and computed its height as 8,840 meters (29,002 feet). At the time it was called Peak XV. It was later named after Sir George Everest, a former Surveyor General of India. In China it is called Qomolangma.

Size comparisons

About 5,200 people 1.7 meters (5 feet 7 inches) tall, standing on each other's heads, would reach the summit.
If Everest stood on the floor of the Challenger Deep, the deepest known point of the Mariana Trench, its summit would still be about 2.1 kilometers (6,800 feet) under water.
Everest is a little taller than the ring of the Large Hadron Collider is wide. The ring is about 8.5 kilometers (5.3 miles) across.
If Earth were shrunk to the size of a basketball, Everest would stand about 0.17 millimeters tall, less than the thickness of two sheets of paper.

Highest, but not tallest

Everest's height is measured from sea level. Measured from its base to its peak, the tallest mountain on Earth is Mauna Kea, a volcano in Hawaii. Mauna Kea starts deep beneath the Pacific Ocean and rises more than 10,210 meters (33,500 feet) from its base.

Everest's summit is not the point farthest from the center of Earth, either. Earth bulges slightly at the equator, because it spins. That bulge puts the summit of Mount Chimborazo in Ecuador, one degree south of the equator, more than 2 kilometers farther from Earth's center than Everest's. Chimborazo is only 6,268 meters (20,564 feet) high.

How the mountain formed

The Himalayas began to form 40 to 50 million years ago, when India, moving north, collided with Asia. Both are carried on tectonic plates, the huge slabs of rock that make up Earth's outer layer. Neither landmass could sink beneath the other, so the rock between them was pushed upward into high peaks. The range now stretches 2,900 kilometers (1,800 miles) along the border between India and Tibet.

The collision has not ended. According to the US Geological Survey, the Himalayas are still rising by more than 1 centimeter (0.4 inches) a year.