1 The officially recognised height of Mount Everest is 29,029ft (8,848m), based on a 1954 ground-based measurement. A disputed satellite-based measurement in 1999 suggested it was six feet taller.
2 There are two main routes to the summit: the south-east ridge from Nepal and the north ridge from Tibet.
3 At Everest’s highest point, you are breathing in a third of the amount of oxygen you would normally breathe due to the atmospheric pressure.
4 At least one person has died on Everest every year since 1969, except in 1977.
5 Sir Edmund Hillary’s son, Peter, has climbed Everest five times.
His first summit was in 1990.
6 Tenzing Norgay unsuccessfully tried to get to the top of Everest six times before reaching it with Hillary.
7 Winds on the mountain have been recorded at more than 200mph.
8 Comparatively, the safest year on Everest was 1993, when 129 reached the summit and eight died (a ratio of 16:1).
9 The deadliest year for climbers of Everest was 1996, when 15 died.
10 One in 10 successful climbs to the summit ends in death.
11 The fastest descent was made in 11 minutes: Frenchman Jean-Marc Boivin paraglided down in 1988.
12 There are estimated to be 120 dead bodies on the mountain.
13 The youngest person to reach the top is Jordan Romero, who made it, aged 13, in 2010.
14 The Nepalese call it Sagarmatha, meaning “Forehead (or Goddess) of the Sky”. In Tibet it is known as Chomolungma, “Mother Goddess of the Universe”.
15 In 1865 the mountain was renamed in honour of the Surveyor General of India George Everest, from its original name of Peak 15.
16 The first woman to climb Everest was Junko Tabei, from Japan, in 1975.
17 A Nepalese government permit to climb Everest can cost up to £17,000.
18 There are 18 named climbing routes on Everest.
19 The most dangerous area on the mountain is Khumbu ice fall, which is thought to have claimed 19 lives.
20 Climbers burn 20,000 calories on the day of the summit climb, and an average of 10,000 a day on the rest of the climb.
21 The record for the most summits is 21, held by 53-year-old Apa Sherpa, known as “Super Sherpa”. His most recent was in 2011.
22 Babu Chiri Sherpa has remained at the summit for the longest single period: 21.5 hours in 1999.
23 Since the first recorded deaths on Everest in 1922, approximately 235 people are believed to have died on the mountain.
24 Avalanches are the foremost cause of death, followed by falls.
25 The first blind person to reach the summit was the American Erik Weihenmayer in 2001.
26 A 1976 US study concluded that Sherpas had undergone genetic adaptations after living in one of the world’s highest regions for thousands of years.
27 Climbers start using bottled oxygen at 26,000ft. It makes a 3,000ft difference in how they feel.
28 The mountain is more than 28 times the height of the Shard.
29 In 1924, the Britons George Mallory, 37, and Andrew Irvine, 22, disappeared on Everest. Whether they reached the summit remains a mystery. In 1999, Mallory’s body was found at 27,000ft.
30 On 30 May 2005, Pem Dorjee Sherpa and Moni Mulepati became the first couple to be married at the summit.
31 The summit is just below the cruising height of a jet (around 31,000ft).
32 An estimated 900lb (400kg) of human waste was removed from the mountain during clear-ups between 2008 and 2011.
33 More than 33,000 feet of fixed rope is used every year to set the South Col route.
34 In 1934, the soldier and eccentric Maurice Wilson attempted to climb Everest solo despite little or no mountaineering experience. His body was found in 1935 near the 23,000ft mark.
35 The Italian climber Reinhold Messner made the first successful solo climb in 1980.
36 Messner’s other record is to be the first to reach the summit without oxygen, achieved with the Austrian Peter Habeler in 1978.
37 Temperatures on the mountain can get as low as minus 60C.
38 Temperatures can surpass 38C in the Western Cwm, which climbers go through to reach the summit.
39 The Australian climber Christian Stangl holds the record for the fastest ascent, made on 25 May 2006. He reached the summit from Camp III – without oxygen – in 16 hours and 42 minutes. The descent took six hours, 48 minutes.
40 On 10 May 1993, 40 climbers reaching the top, the most in any one day.
41 The largest group to climb Everest was a 410-member Chinese team, in 1975.
42 Although Mount Everest is the highest mountain above sea level, Hawaii’s Mauna Kea is the tallest mountain base to peak, measuring a total of 33,500ft, only 13,796ft of which is above sea level.
43 In May 2006, the New Zealander Mark Inglis became the first double amputee to reach the summit. During the ascent he broke one of his prosthetic legs. Adhesive tape temporarily repaired it while a spare was brought up from base camp.
How much does mount Everest grow each year?
Readings suggest that Everest grows 0.1576 inches (about four millimeters) each year. Other tectonic forces, however, may cost Everest some of its height.
44 Everest grows about 4mm higher every year due to geologic uplift.
45 Climbers have left an estimated 120 tons of litter on the mountain, including oxygen tanks, tents and other kit.
46 The country that has lost the most people to the mountain is Nepal, with 46 deaths.
47 Climbers can suffer acute altitude sickness as well as frost bite and hypothermia.
48 The highest 848 metres of the mountain are known as “the death zone”.
49 Sherpa is the name of a nomadic people in eastern Nepal, who also use it as their last name. Usually, their first name is the day of the week on which they were born.
50 In October 1950, expeditions from the north were prohibited after Tibet was invaded by China. The same year, Nepal opened up access to Everest’s south side.