Mount Everest is the highest mountain on Earth above sea level. It stands 29,032 feet (8,849 m) tall. That is more than 5 miles (8 km) straight up. The mountain sits on the border between two countries, Nepal and China.
Why Mount Everest is so hard to climb
Climbing Mount Everest is one of the hardest things a person can do. The mountain is very tall. It is also freezing cold and windy. The air near the top is very thin.
Thin air means there is much less oxygen to breathe. Oxygen is the part of the air your body needs to stay awake and strong. At the top of Everest, every breath has only about a third as much oxygen as a breath at the beach. That is why most climbers carry tanks of oxygen to help them breathe.
The weather makes it even harder. Winds at the top can blow faster than a race car, over 100 miles per hour (160 km/h). The temperature stays below freezing every single day. Climbers wear thick padded suits called down suits to stay warm.
Climbers cannot reach the top in a single day. They spend about two months on the mountain. They rest at camps and take short trips up and down. This gives their bodies time to get used to the thin air before the final climb to the top.
Key Mount Everest facts
How tall. Mount Everest is 29,032 feet (8,849 m) above sea level. Nepal and China measured it together in 2020 and agreed on that number.
Where it is. It sits on the border between Nepal and China, in a huge chain of mountains called the Himalayas. The Himalayas have many of the tallest mountains in the world.
Three names. People in different places call it different things. In Nepal it is Sagarmatha. In Tibet it is Chomolungma. The English name honors a man named George Everest.
First to the top.Edmund Hillary of New Zealand and Tenzing Norgay, a Sherpa from Nepal, were the first people to reach the very top, on May 29, 1953.
Youngest climber.Jordan Romero, an American boy, reached the top in 2010 when he was just 13 years old. He climbed with his dad and a team of guides.
Most climbs. A guide named Kami Rita Sherpa has reached the top more than 30 times, more than anyone else in the world.
Always cold. The temperature at the top stays below freezing all year. In winter it can drop to -76 °F (-60 °C).
Always snowy. It is so cold that the snow on top never melts, even in summer.
Still growing. The mountain gets a tiny bit taller each year, less than the width of a pencil. Two huge pieces of land under the ground are slowly pushing against each other.
Sherpa climbers
The Sherpa are a group of people who live high in the mountains of Nepal. Many Sherpa families have lived up high for hundreds of years. Because of that, their bodies are very good at handling thin air.
Sherpa climbers do some of the most important work on Everest. They carry heavy loads, fix safety ropes, and guide other climbers to the top. Most people who reach the summit only get there with the help of Sherpa guides. Kami Rita Sherpa, the record holder, is one of them.
Common myths about Mount Everest
Myth: Mount Everest is the tallest mountain by every way of measuring. Everest is the highest above sea level. But a volcano in Hawaii called Mauna Kea is taller from its base to its top, because most of it is hidden underwater.
Myth: Edmund Hillary climbed Everest without oxygen tanks. Hillary and Tenzing Norgay both used bottled oxygen near the top in 1953. The first people to climb it without oxygen did not do so until 1978.
Myth: Helicopters fly climbers to the very top. The air near the top is too thin for helicopters to fly safely. Climbers reach the top on foot.
Myth: The rocks on top of Everest are dinosaur fossils. The summit rocks hold fossils of tiny sea creatures, not dinosaurs. The rocks are about 450 million years old, much older than any dinosaur.
Frequently asked questions about Mount Everest
How tall is Mount Everest?
Mount Everest is 29,032 feet (8,849 m) above sea level. That is the height Nepal and China agreed on in 2020. It is the highest point on land in the whole world.
Where is Mount Everest?
Mount Everest is in Asia, on the border between Nepal and China. The southern side is in Nepal. The northern side is in Tibet, which is part of China. Both sides share the top.
Who was the first person to climb Mount Everest?
Edmund Hillary of New Zealand and Tenzing Norgay of Nepal reached the top first, on May 29, 1953. They climbed as part of a British team. The news reached the rest of the world a few days later.
Why is the air so thin at the top?
Air is held close to the ground by gravity. The higher you go, the less air there is. At the top of Everest, each breath gives you only about a third of the oxygen you would get at sea level. That is why climbers bring oxygen tanks.
How do the rocks on top have sea fossils?
A very long time ago, the rock that is now the top of Everest was at the bottom of an ocean. Two giant pieces of land crashed together and pushed the old seafloor high into the sky. The tiny sea fossils went up with it.
Each quiz question cites a source for the fact it tests. You can play the Mount Everest trivia quiz at the Rookie level, a 10-question true-or-bluff round for kids.
Mount Everest is the highest mountain on Earth measured above sea level, standing 29,032 feet (8,849 m) on the border between Nepal and China. It is part of the Himalayas, the mountain chain that holds most of the world’s tallest peaks. Edmund Hillary of New Zealand and Tenzing Norgay, a Sherpa from Nepal, were the first people confirmed to reach the summit, on May 29, 1953. By the end of 2024, more than 12,000 successful climbs to the top had been recorded.
Why Mount Everest is so dangerous
Three things make Everest deadly, and they add to each other.
The first is the thin air. The amount of oxygen in air stays the same at every height, but the air itself gets thinner as you climb. At the summit, the air pressure is about a third of what it is at sea level, so each breath delivers only about a third as much oxygen. The slopes above 26,247 feet (8,000 m) are called the death zone, because the body breaks down faster than it can recover, even with bottled oxygen.
The second is the weather. A fast band of high-altitude wind called the jet stream sits over Everest most of the year. Summit winds often top 100 miles per hour (160 km/h) and can reach 200 mph (320 km/h) in winter. The mountain is only safe to climb during short calm spells, mostly in May and again in late September and October.
The third is falling ice. Just above Base Camp, the slow-moving Khumbu Glacier breaks into a jumble of giant ice blocks called the Khumbu Icefall. The ice creeps downhill about 3 to 4 feet (1 m) a day, so the blocks can lean and topple without warning. In 2014, a single ice avalanche there took the lives of 16 Sherpa climbers, the worst day on the mountain at the time.
Key Mount Everest facts
Official height. 29,032 feet (8,849 m) above sea level, set by a joint Nepal-China survey announced on December 8, 2020. The exact figure is 29,031.69 feet (8,848.86 m).
Location. On the border between Nepal and China, in the Mahalangur section of the Himalayas. The Nepali side lies inside Sagarmatha National Park.
Three names.Mount Everest in English (named for British surveyor George Everest in 1865), Sagarmatha in Nepali, and Chomolungma in Tibetan.
First ascent. Edmund Hillary and Tenzing Norgay, May 29, 1953, on a British team led by Colonel John Hunt. The news reached Britain on June 2, the morning of Queen Elizabeth II’s coronation.
First without bottled oxygen. Reinhold Messner of Italy and Peter Habeler of Austria, on May 8, 1978. Many doctors had thought this was impossible.
First woman to summit. Junko Tabei of Japan, on May 16, 1975.
Most ascents. Kami Rita Sherpa of Nepal, with 31 summits, the most recent on May 27, 2025.
Youngest climber. Jordan Romero of the United States, age 13, in 2010. Oldest climber. Yuichiro Miura of Japan, age 80, in 2013.
Total deaths. More than 340 since climbing records began in 1922. The first recorded deaths were 7 Sherpas killed in an avalanche that year.
Summit temperature. Around 0 °F (-18 °C) in summer, dropping below -76 °F (-60 °C) in winter.
Summit rock. Limestone about 450 million years old, formed on an ancient seafloor. Climbers near the top can find fossils of small sea animals in the gray-yellow rock.
How the height was settled
For decades, different countries listed slightly different heights for Everest. Part of the puzzle was the snow. Nepal measured to the top of the snow cap. China measured the rock underneath. They disagreed by a few feet.
In 2020, surveyors from both countries climbed the peak and combined their data using GPS receivers and ground-leveling tools. They agreed on a single number, 29,031.69 feet (8,848.86 m), and both governments now accept it. The mountain is also rising a few millimeters a year, because the Indian plate keeps pushing north into the rest of Asia.
The Sherpa community
The Sherpa are an ethnic group in Nepal, many of whom have lived at altitudes of 10,000 to 14,000 feet (3,000 to 4,300 m) for generations. Growing up that high gives most adult Sherpas a head start on the thin air that lowland climbers reach only after weeks of training on the mountain.
Sherpas are not magically immune to altitude. No human is. But they do most of the toughest work on Everest: carrying loads, setting up camps, and fixing the safety ropes that other climbers clip into. Most modern summit successes depend directly on Sherpa support.
Common myths about Mount Everest
Myth: Mount Everest is the tallest mountain by every measure. Everest is the highest point above sea level. Mauna Kea in Hawaii is taller measured from base to summit, because most of the volcano sits underwater. Chimborazo in Ecuador is farther from the center of the Earth, because the planet bulges at the equator.
Myth: Bottled oxygen makes the death zone safe. Even with a tank, the body keeps deteriorating above 26,247 feet (8,000 m). Bottled oxygen helps climbers think clearly and move faster, but time in the death zone must still be kept short.
Myth: Climbing Everest is mostly a one-day push. A full expedition takes about two months. Climbers spend weeks moving up and down the lower mountain to let their bodies adjust before the final summit day.
Myth: Helicopters can land on the summit. The air near the top is too thin for rotors to lift a helicopter and crew. In 2005, a pilot briefly touched a specially modified helicopter onto the summit, but it did not carry passengers or cargo.
Myth: Mount Everest is in India. It sits on the Nepal-China border. The mix-up partly comes from the fact that George Everest, whom the peak is named after, was the British Surveyor General of India.
Frequently asked questions about Mount Everest
Why is the official height 29,031.69 feet (8,848.86 m)?
Surveyors from Nepal and China measured the peak with GPS receivers, gravity meters, and ground-leveling tools. They combined their results and announced the agreed figure in December 2020. It includes the snow cap on top.
How many people have died on Mount Everest?
More than 340 climbers have died since records began in 1922. 16 of those deaths happened on a single day, April 18, 2014, when an ice avalanche struck the Khumbu Icefall. The death rate among climbers attempting the modern route is roughly 1 percent.
Why does Everest keep getting taller?
The Indian plate is still sliding north into the rest of Asia at about 2 inches (5 cm) a year. The crash pushes the Himalayas upward. Everest itself rises a few millimeters a year, though erosion wears some of that height back down.
What is the death zone?
The death zone is the part of the mountain above 26,247 feet (8,000 m). The air pressure is so low there that the body cannot recover from the effort, even with bottled oxygen. Climbers try to spend as little time as possible at that height.
Who climbs Everest the most?
Sherpa guides from Nepal. Kami Rita Sherpa holds the record with 31 summits as of 2025. Sherpas grew up at high altitude and do most of the load-carrying and rope-fixing that other climbers rely on.
Each quiz question cites a source for the fact it tests. You can play the Mount Everest trivia quiz at the Curious level, a 10-question true-or-bluff round.
Mount Everest is the highest mountain on Earth above sea level, standing 29,031.69 ft (8,848.86 m) on the border between Nepal and China. It rises in the Mahalangur subrange of the Himalayas, the chain pushed up by the ongoing collision of the Indian and Eurasian tectonic plates. Edmund Hillary of New Zealand and Tenzing Norgay, a Sherpa from Nepal, became the first confirmed climbers to reach the summit at 11:30 a.m. on May 29, 1953, on the British expedition led by Colonel John Hunt. As of the end of 2024 the mountain had been summited more than 12,000 times by individual climbers and had taken the lives of more than 340 people.
Why Mount Everest is so hard to climb
Mount Everest is dangerous for 3 reasons that compound each other.
The first is air pressure. The summit sits in an atmospheric pressure of roughly 309 to 343 hectopascals, about a third of sea level. Because the fraction of oxygen in air stays constant at 21 percent regardless of altitude, that pressure cut means each breath delivers about a third as much oxygen as the same breath at the beach. A sea-level dweller transported to the summit without acclimatization would lose consciousness in 2 to 3 minutes. The ‘death zone’ (the slopes above 26,247 ft / 8,000 m) is named for the fact that the human body deteriorates faster than it can recover above this altitude, even with bottled oxygen.
The second is weather. The jet stream sits over Everest most of the year, and summit winds routinely exceed 100 mph (160 km/h) and can reach 200 mph (320 km/h) in winter. The mountain only becomes climbable in narrow weather windows: the main pre-monsoon window in late April and May, and a smaller post-monsoon window in late September and October. The 1996 storm that killed 8 climbers (including Adventure Consultants founder Rob Hall and Mountain Madness founder Scott Fischer) was an unforecast deterioration of one such window.
The third is glacial and rock hazard. The Khumbu Icefall, the lower section of the Khumbu Glacier just above Base Camp, advances down the mountain at about 3 to 4 ft (0.9 to 1.2 m) per day, breaking into car-sized seracs that lean and collapse without warning. The 2014 ice avalanche, the worst single-day disaster in Everest history at the time, killed 16 Sherpa climbers in the Khumbu Icefall on April 18 of that year. The 2015 Gorkha earthquake triggered a separate avalanche off Pumori that struck Base Camp and killed at least 19 people.
Key Mount Everest facts
Height. 29,031.69 ft (8,848.86 m) above sea level, set by the 2020 joint Nepal-China survey announced December 8, 2020. The previous standard figure was 8,848 m. Geodetic measurements suggest the mountain is rising a few millimeters a year as the Indian Plate continues pushing into Eurasia.
Location. On the border of Khumbu, Nepal and Tibet (China), in the Mahalangur Himal subrange of the Himalayas. The Nepali side falls within Sagarmatha National Park, a UNESCO World Heritage Site since 1979.
Names. Mount Everest (English, named for Sir George Everest by the Royal Geographical Society in 1865), Sagarmatha (Nepali, ‘Goddess of the Sky’), and Chomolungma (Tibetan, ‘Goddess Mother of the World’).
First confirmed ascent. Edmund Hillary (New Zealand) and Tenzing Norgay (Sherpa, Nepal/India), May 29, 1953, on the British expedition led by Colonel John Hunt. South Col route. The news broke on June 2, the morning of Queen Elizabeth II’s coronation.
First ascent without supplemental oxygen. Reinhold Messner (Italy) and Peter Habeler (Austria), May 8, 1978. Messner returned in August 1980 to make the first solo ascent, again without bottled oxygen.
First woman to summit. Junko Tabei (Japan), May 16, 1975, on the Japanese Women’s Everest Expedition.
First American to summit. Jim Whittaker, May 1, 1963, with Sherpa Nawang Gombu, on the American Mount Everest Expedition led by Norman Dyhrenfurth.
Most ascents. Kami Rita Sherpa of Nepal, 31 summits, most recent on May 27, 2025. Pasang Dawa Sherpa is second with 29.
Youngest summit. Jordan Romero (USA), May 22, 2010, age 13 years 10 months. Climbed from the Tibetan side because Nepal does not permit climbers under 16.
Oldest summit. Yuichiro Miura (Japan), May 23, 2013, age 80 years 223 days.
Total deaths. More than 340 since recorded climbing began in 1922, when 7 Sherpas were killed in an avalanche on the North Col during the 1922 British expedition.
Worst single-day disasters. April 18, 2014 ice avalanche in the Khumbu Icefall (16 dead). May 10 to 11, 1996 storm (8 dead). April 25, 2015 avalanche off Pumori onto Base Camp during the Gorkha earthquake (at least 19 dead).
Summit rock. Ordovician limestone roughly 450 million years old, deposited in a shallow Tethyan Sea long before the Indian-Eurasian collision and uplifted into its current position by tectonic activity. Climbers near the summit can find marine fossils (brachiopods, conodonts, crinoids) in the gray-yellow rock.
Summit air temperature. Around 0°F (-18°C) in summer; can drop below -76°F (-60°C) in winter.
Common myths about Mount Everest
Myth: Mount Everest is the tallest mountain on Earth. Everest is the highest point above sea level, but Mauna Kea in Hawaii is taller measured base-to-summit. Mauna Kea’s summit stands 13,800 ft (4,205 m) above sea level, but its base sits 19,700 ft (6,000 m) below the Pacific surface, for a total of about 33,481 ft (10,205 m). Measured from the center of the Earth, Chimborazo in Ecuador wins because the equator bulges outward; Everest is at about 28 degrees north and sits closer to Earth’s center.
Myth: Edmund Hillary and Tenzing Norgay climbed Everest without oxygen. Hillary and Tenzing both used bottled oxygen above the South Col on May 29, 1953. The first oxygen-free ascent did not occur until May 8, 1978, when Reinhold Messner and Peter Habeler proved that the pre-1978 medical consensus (that humans could not survive above 8,500 m without bottled oxygen) was wrong.
Myth: Mallory and Irvine reached the summit in 1924. They may have. Mallory and Irvine disappeared on the Northeast Ridge on June 8 or 9, 1924, having been seen at about 800 vertical feet from the summit through breaks in the cloud. Mallory’s body was found in 1999 at 26,760 ft (8,160 m); Irvine’s partial remains in 2024. The camera that might hold a summit photograph has not been recovered. Whether they reached the top before dying is unresolved.
Myth: Mount Everest is in India. It is on the Nepal-China border. India does not share the mountain. The colonial-era confusion partly comes from the fact that Sir George Everest (after whom the peak was named) was the British Surveyor General of India, and that the surveys were conducted from British India.
Myth: Helicopters can land on the summit. Air density above the South Col is too thin for helicopter rotors to generate the lift needed to land or take off safely with crew and load. The exception is the May 14, 2005 record landing of a specially modified Eurocopter AS350 B3 by pilot Didier Delsalle, who briefly touched down on the summit but did not pick up or unload anything.
Myth: George Everest climbed the mountain that bears his name. Sir George Everest never visited the mountain or attempted to climb it. He opposed having it named after him, on the grounds that local Nepali and Tibetan names should be preferred; the Royal Geographical Society used his name anyway in 1865 over his objection.
Myth: Climbing Everest is mostly a 1-day push to the summit. A guided expedition typically takes about 2 months from arrival in Nepal to departure, with weeks of acclimatization rotations on the lower mountain before the final summit push. The summit-day climb itself is usually a single 12 to 18 hour effort from the South Col, but the rest of the expedition is a slow climb-and-descend pattern designed to acclimatize the body to thin air.
Frequently asked questions about Mount Everest
How many people have summited Mount Everest, and how many have died?
By the end of the 2024 climbing season, Everest had been summited by more than 7,000 distinct individuals across more than 12,000 successful summits (some climbers, especially Sherpa guides, summit repeatedly). The cumulative confirmed death toll exceeds 340. 16 recorded fatalities occurred on a single bad day (April 18, 2014, in the Khumbu Icefall). The general death rate among climbers attempting to summit on the modern, commercial South Col route is roughly 1 percent. The worst recent year was 2023, with 18 deaths or disappearances; 2024 saw a sharp drop to 8 to 9, partly attributed to better permit screening.
Why does Everest grow taller every year, and by how much?
The Indian tectonic plate is still moving north into Eurasia at roughly 2 in (5 cm) per year. The collision crumples and uplifts the rocks of the Himalayas; geodetic measurements indicate Everest itself rises a few millimeters a year, with erosion partly canceling the uplift. Major earthquakes can reset the value: the 2015 Gorkha earthquake measurably shifted the position of GPS markers on the mountain, although the change in height was less than a few centimeters. The original sea-floor rocks at the summit are now roughly 9 km above the elevation at which they formed about 450 million years ago.
What is the cheapest legal way to climb Everest?
There is no cheap legal way. The Nepalese government’s permit fee is set at $11,000 per climber for the standard pre-monsoon season, and that is the smallest line item on the budget. A fully guided commercial expedition with a Western operator costs $40,000 to $100,000 or more, including Sherpa support, oxygen, medical, and rescue insurance. Lower-cost Nepali-led operations have driven prices down at the entry level but raised concerns about training and emergency capacity. The Tibetan side requires permits issued through the Chinese government and is intermittently closed to foreign climbers.
Why are bodies left on the mountain?
The death zone is too high and too unstable for routine recovery. Most bodies sit at altitudes where helicopter rescue cannot operate (above the South Col on the Nepal side), and a recovery team would need to spend hours in the death zone to handle and lower the body, multiplying the rescuers’ own risk. A documented retrieval can cost $30,000 to $80,000, and the expedition is itself dangerous; several rescuers have died trying. As a result, more than 200 bodies are believed to remain on the mountain. A stretch of the Northeast Ridge is informally known as ‘Rainbow Valley’ for the colorful jackets visible on long-dead climbers.
Who is Kami Rita Sherpa, and why does the Sherpa community dominate Everest?
Kami Rita Sherpa, 55, was born in Thame in the Khumbu region of Nepal and first summited Everest in May 1994. He has summited Everest 31 times as of May 27, 2025, more than any other climber in history. The Sherpa population of Nepal is roughly 250,000 nationwide, with only a few thousand living in the Khumbu region itself; the community has produced more high-altitude guides, route-fixers, and load-carriers than any other ethnic group on Earth. Sherpas are not biologically immune to altitude (no human is), but they have lived for generations at altitudes of 10,000 to 14,000 ft, which gives most adult Sherpas a baseline acclimatization that lowland climbers reach only after weeks of rotations. Their economic role on the mountain is enormous: most commercial summit successes depend directly on Sherpa labor.
You can test these facts on the Mount Everest trivia quiz, a 10-question true-or-bluff round at the Sharp reading level.
Mount Everest is the highest point on the Earth’s surface measured above mean sea level, standing 29,031.69 feet (8,848.86 m) on the border between Nepal and the Tibet Autonomous Region of China. It is the dominant peak of the Mahalangur Himal, a subrange of the Greater Himalaya raised by the ongoing continental collision of the Indian and Eurasian plates. The first confirmed ascent was made by Edmund Hillary of New Zealand and Tenzing Norgay, a Sherpa of Nepal and India, at about 11:30 a.m. on May 29, 1953, on the British expedition led by Colonel John Hunt. By the end of 2024 the mountain had been summited more than 12,000 times and had recorded more than 340 deaths.
Why Everest sits at the edge of human tolerance
Everest’s danger is the product of three independent hazard systems that overlap on the same slopes: barometric, meteorological, and glacial.
The atmospheric problem is the most fundamental. The fraction of oxygen in air stays fixed at about 21 percent regardless of altitude, so the limiting variable is the partial pressure of oxygen, which falls with the total barometric pressure. Pressure decline with height is approximately exponential, governed by the hydrostatic balance of the atmosphere and the temperature lapse rate. The first direct measurement on the summit was made by Christopher Pizzo during the 1981 American Medical Research Expedition to Everest, who recorded a barometric pressure of about 253 Torr, roughly a third of the sea-level value near 760 Torr. That is enough to render the death zone, the slopes above 26,247 feet (8,000 m), a place where the body’s oxygen delivery cannot keep pace with the cost of effort, and where deterioration outruns recovery even on bottled oxygen.
The meteorological problem is the jet stream. For most of the year a band of high-altitude wind sits across the summit, driving sustained winds that routinely exceed 100 mph (160 km/h) and can reach 200 mph (320 km/h) in winter. Climbing is feasible only in narrow weather windows when the jet stream lifts off the peak: the principal pre-monsoon window in late April and May, and a shorter post-monsoon window in late September and October. The unforecast deterioration of one such window on May 10 and 11, 1996 trapped multiple commercial teams above the South Col and killed 8 climbers in 24 hours, including the expedition leaders Rob Hall of Adventure Consultants and Scott Fischer of Mountain Madness.
The glacial problem is the Khumbu Icefall, the chaotic lower section of the Khumbu Glacier between Base Camp at about 17,600 feet (5,365 m) and Camp 1 near 19,500 feet (5,943 m). Here the glacier descends a steep step in the bedrock and breaks into a maze of seracs (towering blocks of ice) and crevasses. The ice advances roughly 3 to 4 feet (about 1 m) per day, so the towers lean, collapse, and reshape the route through the season. A team of Sherpa route-setters known as the Icefall Doctors rebuilds the path each year with fixed ropes and aluminum ladders. The April 18, 2014 ice avalanche in the icefall killed 16 Sherpa climbers, and the 2015 Gorkha earthquake triggered a separate avalanche off Pumori that struck Base Camp and killed about 22 people.
Key Mount Everest facts
Geodetic height. 29,031.69 feet (8,848.86 m) above mean sea level, the figure adopted jointly by Nepal and China and announced on December 8, 2020. The survey reconciled a long-standing disagreement: Nepal’s tradition of measuring to the snow cap against China’s earlier preference for the rock head. The standard pre-2020 value had been 29,029 feet (8,848 m).
Tectonic setting. Everest lies in the Mahalangur Himal of the Greater Himalaya, raised by the collision of the Indian Plate with Eurasia that began about 50 million years ago. India continues to converge on Eurasia at roughly 2 inches (5 cm) per year, and geodetic data place the current uplift of the peak at a few millimeters per year, partly offset by erosion.
Summit stratigraphy. The summit pyramid is the Qomolangma Formation, Ordovician marine limestone roughly 450 million years old, deposited in the shallow Tethyan Sea long before uplift. It yields fossils of brachiopods, conodonts, and crinoids. Lower on the route lies the Yellow Band, a unit of metamorphosed limestone (marble) below the summit pyramid, whose weathered marble carries crinoid fragments.
Toponymy.Mount Everest is the English name, adopted by the Royal Geographical Society in 1865 on the recommendation of Surveyor General Andrew Waugh, over the objection of Sir George Everest himself, who never visited the peak and favored a local name. The mountain had been cataloged as Peak XV. The Nepali name is Sagarmatha and the Tibetan is Chomolungma.
First confirmed ascent. Hillary and Tenzing, May 29, 1953, via the South Col and Southeast Ridge, the route established by Hunt’s expedition. They surmounted the rock pitch near 28,839 feet (8,790 m) later named the Hillary Step, a feature substantially altered after the 2015 earthquake.
First ascent without supplemental oxygen. Reinhold Messner of Italy and Peter Habeler of Austria, May 8, 1978, overturning the pre-1978 medical consensus that survival above 27,900 feet (8,500 m) required bottled oxygen. Messner returned in August 1980 for the first solo ascent, again oxygen-free, by the North Col and North Ridge route over 3 days, summiting on August 20.
Other records. First woman to summit: Junko Tabei of Japan, May 16, 1975. First American: Jim Whittaker, May 1, 1963. Youngest: Jordan Romero of the United States, age 13, in 2010 (from the Tibetan side, since Nepal does not permit climbers under 16). Oldest: Yuichiro Miura of Japan, age 80, in 2013. Most ascents: Kami Rita Sherpa of Nepal, 31 summits as of May 27, 2025.
Mortality. More than 340 deaths since recorded climbing began in 1922, when 7 Sherpas were killed in an avalanche on the slopes leading to the North Col during the 1922 British expedition. The single deadliest day was the April 18, 2014 ice avalanche (16 dead).
Summit climate. Air temperature around 0 °F (-18 °C) in summer, falling below -76 °F (-60 °C) in winter.
Physiology of the death zone
The phrase “death zone” is a physiological designation, not a topographic one. At the summit pressure near 253 Torr, the inspired partial pressure of oxygen is roughly a third of the sea-level value, and the body compensates through several linked responses. Sustained hypoxia drives the hypoxic ventilatory response, increasing breathing rate and depth; the resulting loss of carbon dioxide raises blood pH toward respiratory alkalosis, which over days is partly corrected by the kidneys. Acclimatization over weeks also raises hemoglobin concentration through erythropoietin release, increasing the oxygen-carrying capacity of each unit of blood.
How far this carries a climber was quantified by the 2007 Caudwell Xtreme Everest expedition, which sampled arterial blood from climbers high on the mountain and published the results in the New England Journal of Medicine in 2009. At an altitude where the barometric pressure was about 272 mmHg, climbers breathing ambient air showed a mean arterial oxygen partial pressure of 24.6 mmHg, with individual values as low as 19.1 mmHg, levels that would be rapidly fatal in an unacclimatized person at sea level but that adapted climbers can briefly tolerate. The samples were not taken on the summit itself, where pressure is lower still, but they remain among the most extreme human blood-gas measurements ever recorded.
The two acute, life-threatening illnesses of altitude are distinct in mechanism. High-altitude pulmonary edema (HAPE) is a non-cardiogenic leak of fluid into the lungs, driven by uneven hypoxic pulmonary vasoconstriction. High-altitude cerebral edema (HACE) is brain swelling from increased cerebral blood flow and vascular permeability. Both can progress within hours, and both respond reliably only to descent, supplemental oxygen, and pharmacologic support. The practical consequence on Everest is that summit windows are run as fast as physiology allows: a typical summit day from the South Col is a single 12 to 18 hour effort, surrounded by an expedition of about two months built around acclimatization rotations on the lower mountain.
How the height has been measured over time
The elevation of Everest is a moving target on several timescales, and the published figures reflect changes in method, in the definition of the summit, and in the rock itself.
The first credible value came from the Great Trigonometrical Survey of British India. Using triangulation chains carried up from the Indian plain, the survey computed a height for Peak XV that was published in 1856 as 29,002 feet (8,840 m). The widely repeated story is that the raw computation came to a suspiciously round 29,000 feet, and that Andrew Waugh added a token 2 feet so the figure would not look like an estimate. Twentieth-century surveys revised the number repeatedly: an Indian survey in the 1950s settled on 29,028 feet (8,848 m), and a 1999 American expedition using GPS reported about 29,035 feet (8,850 m) to the snow surface.
The 2020 joint Nepal-China survey resolved the discrepancy by deploying GNSS satellite receivers, gravimeters to model the local geoid, and ground-leveling, and by agreeing in advance on what would be counted as the top. The published 29,031.69 feet (8,848.86 m) is the snow height. Underlying all of this is genuine geophysical motion: the Indian Plate continues to drive the range upward at a few millimeters per year, and major earthquakes can offset the summit. The 2015 Gorkha event, magnitude 7.8 with an epicenter about 140 miles (220 km) west of the peak, shifted GPS markers across the region, though the change in Everest’s own height was at the level of a few centimeters at most.
The early climbing record
Organized attempts on Everest began only after Tibet opened its northern approaches to British expeditions in the 1920s; both Tibet and Nepal had been closed to outside surveyors before then, which is one reason no earlier ascent or fatality is on record. The 1921 reconnaissance mapped the approach, and the 1922 expedition under Charles Granville Bruce made the first serious summit bid. That expedition produced both a milestone and a tragedy: George Finch and Geoffrey Bruce reached about 27,300 feet (8,320 m) using the first practical bottled-oxygen apparatus, the highest verified altitude any human had then attained, and an avalanche on the North Col slopes killed 7 Sherpa porters, the first deaths recorded on the mountain.
The most enduring mystery belongs to the 1924 expedition. George Mallory and Andrew Irvine set out for the summit on the Northeast Ridge and were last seen, through a break in the cloud, a few hundred vertical feet from the top before they disappeared on June 8 or 9, 1924. Mallory had given the line most associated with the mountain, “Because it’s there,” to a reporter during a 1923 fundraising tour in the United States. His body was found in 1999 at 26,760 feet (8,160 m), and remains believed to be Irvine’s emerged from the Central Rongbuk Glacier in 2024. The camera that might settle whether they reached the summit before dying has not been recovered, and the question remains open.
Common myths about Mount Everest
Myth: Everest is the tallest mountain on Earth. It is the highest point above sea level, but Mauna Kea in Hawaii is taller measured base to summit, at about 33,500 feet (10,210 m) from the Pacific seafloor, and Chimborazo in Ecuador is the point farthest from the Earth’s center because of the equatorial bulge. The three claims use three different reference surfaces.
Myth: Hillary and Tenzing climbed without oxygen. Both used open-circuit bottled oxygen above the South Col in 1953. The first oxygen-free ascent waited until Messner and Habeler in 1978.
Myth: The Himalayas are volcanic. They are a continent-continent collisional orogen, not a volcanic arc. The summit rock is uplifted marine sedimentary limestone, and the few “sulfur layer” or “granite summit” claims that circulate are simply wrong about the geology.
Myth: The death zone kills by slow suffocation. The mechanism is more specific than that. Sustained hypoxia produces hyperventilation, respiratory alkalosis, hypoxic pulmonary vasoconstriction, and progressive pulmonary or cerebral edema, and decompensation can be abrupt. Cognitive impairment sets in well before any loss of consciousness.
Myth: Helicopters routinely operate at the summit. Air density above the South Col is too low for sustained rotor lift with crew and load. The lone exception is the May 14, 2005 record in which pilot Didier Delsalle briefly set a specially modified Eurocopter AS350 B3 on the summit without taking on passengers or cargo.
Myth: George Everest climbed the mountain that bears his name. He never visited it and opposed the naming. The Royal Geographical Society applied his name in 1865 over his stated objection that a local toponym was preferable.
Frequently asked questions about Mount Everest
Why is the official height 29,031.69 feet (8,848.86 m)?
That value comes from the 2020 joint Nepal-China survey, which combined GNSS satellite positioning, a gravimetric geoid model, and ground-leveling, and which agreed in advance to publish the snow height. It superseded the long-standard 8,848 m and reconciled the snow-versus-rock disagreement between the two countries.
What makes the death zone lethal even with bottled oxygen?
Above 26,247 feet (8,000 m) the ambient partial pressure of oxygen is so low that supplemental oxygen narrows the deficit without erasing it. The body continues to deteriorate, and acute illnesses such as HAPE and HACE can develop within hours. Bottled oxygen buys speed and clearer cognition, not immunity, which is why time in the zone is minimized.
How fast does the Khumbu Icefall move, and why is that dangerous?
The icefall advances roughly 3 to 4 feet (about 1 m) per day as the Khumbu Glacier flows over a steep bedrock step. That motion fractures the ice into seracs and crevasses that shift, collapse, and form unstable bridges, and the route through it has to be rebuilt and re-routed across the season.
Is Everest still rising?
Yes, slowly. The India-Eurasia collision continues at roughly 2 inches (5 cm) per year of plate convergence, driving uplift of the peak at a few millimeters per year, partly canceled by erosion. Large earthquakes can offset the summit by centimeters in a single event.
Did Mallory and Irvine reach the summit in 1924?
It is unresolved. They were seen high on the Northeast Ridge before disappearing on June 8 or 9, 1924. Mallory’s body was found in 1999 and remains believed to be Irvine’s in 2024, but the camera that might confirm a successful summit has never been recovered.
Each quiz question cites a primary source for the specific fact tested. You can play the Mount Everest trivia quiz at the Expert level, a 10-question true-or-bluff round.
