Mount Everest is the most famous mountain on Earth, yet much of what people "know" about it is out of date or wrong. Its height was only settled a few years ago, it is still moving, and its summit is made of ancient seabed. Nepal's rules for climbing it keep changing, and 2026 broke the summit record. Whether you are planning an Everest Base Camp trek or just curious, these 20 facts, drawn from the latest data and the guides who work there every season, will change how you see the mountain.
Geology and the Changing Height
1. The official height was only agreed in 2020. Nepal and China jointly announced a figure of 8,848.86 metres (29,031.69 ft), replacing the earlier accepted 8,848 metres. It was also the first time Nepal carried out its own measurement of the peak. The new number was 86 cm higher than Nepal's previous figure, and China's older number had measured the rock beneath the snow rather than the snow and ice cap. 8,848.86 metres. That’s the height of Mt Everest now +2
2. Everest is still growing, and earthquakes can shrink it. Its height changes with tectonic uplift of about 4 millimetres a year, sudden earthquake movement, and seasonal changes to the snow cap. The 2015 Gorkha earthquake is thought to have lowered it by about 2.5 cm. Even the "official" number is a snapshot. Explore Vision NepalExploreallaboutnepal
3. The summit is an ancient seafloor. The top is Ordovician limestone laid down on a shallow tropical sea around 450 million years ago, with trilobite and crinoid fossils found within about six metres of the true summit. The Indian plate slammed into Asia roughly 55 million years ago and has not stopped pushing. TravelhimalayanepalTravelhimalayanepal
4. Everest has never had just one name. British mapmakers first knew it as Peak XV, and it was renamed in 1865 after Sir George Everest. Everest himself never set foot near the mountain. Sherpas and Tibetans call it Chomolungma, "goddess mother of the world", and Nepal calls it Sagarmatha, "peak of the sky". Nepal officially adopted Sagarmatha in the 1960s. 70 Years Since First Humans Climbed Mount Everest +3
Weather and the Death Zone
5. At the summit, every breath holds about a third of the oxygen. Air pressure at the top is around one-third of sea-level pressure. A climber breathes at the same rate as at sea level, but each breath delivers only a third of the oxygen molecules. Live For The OutdoorsNepal Intrepid Treks
6. A river of wind sits on the summit for most of the year. For around 250 days a year the upper slopes are hit by jet-stream winds reaching 175 mph. Summit temperatures average about −36°C and fall to around −60°C in winter. Climbing is only feasible in windows of three to seven days when the jet stream shifts away. Inside the death zone: Why Everest is so dangerous +2
7. Above 8,000 metres, the body cannot adapt. Acclimatisation becomes impossible in the "Death Zone". A Swiss physician coined the term in 1952. Since 1953 only 232 climbers, about 1.7% of summiters, have reached the top without supplemental oxygen, and members using oxygen were roughly twenty times more likely to summit. Inside the death zone: Why Everest is so dangerous +2
8. Trekkers feel the cold too. Base Camp at 5,364 metres ranges from about −17°C to 2°C. On Global Nepal Treks' Everest Base Camp itinerary, temperatures at the Kala Patthar sunrise viewpoint can drop below −15°C, so warm batteries and layers matter as much as fitness. Nepal Intrepid Treks
Human History and Sherpa Culture
9. In 1953, reaching the summit took the ninth expedition, and the walk in took months. Hillary and Tenzing's 1953 climb was the ninth attempt on the summit, and the first 600 people took 20 years to summit. Today that many can climb in one season. The journey to Base Camp fell from months to eight days once the Lukla airstrip opened in 1964. Voice of AmericaVoice of America
10. One man has climbed Everest 32 times. Kami Rita Sherpa, 56, reached the summit for the 32nd time in May 2026, breaking his own record. He was born in Thame, the village that also produced Tenzing Norgay. CNNTrue Summit
11. More Sherpas than paying clients have stood on top. Hired climbers, mostly Sherpas, have recorded about 7,081 summits against roughly 6,656 by clients. The same source records that they account for 130 of Everest's 339 deaths, a reminder of who carries the mountain's risk. Alan Arnette
12. For Sherpas, Everest is a goddess, and expeditions begin with prayer. Every expedition starts with a puja ceremony honouring the mountain, and Tengboche Monastery has overlooked Everest for centuries. Trekkers walk past Tengboche on the Base Camp route. Alpine Ramble Treks
13. Women have made Everest history too. Japan's Junko Tabei became the first woman to summit, in 1975, and Reinhold Messner made the first solo ascent in 1980. In 2026 Lakhpa Sherpa completed her 11th ascent, the most by any woman. Encyclopedia BritannicaTechnology Org
[Draft quote, to confirm with the guide before publishing] "Trekkers ask about the summit. I tell them the real story starts at Namche. If you respect the pace, Everest respects you." — [Guide name], Senior Trek Leader, Global Nepal Treks
Environmental Challenges
14. Climbers must bring their rubbish down. Since 2015 the Sagarmatha Pollution Control Committee has enforced an 8 kg rule, with at least 2 kg from Camp 2 and above from the 2026 season, plus mandatory human waste bags. Nepali Times
15. Melting ice is exposing decades of old waste. In spring 2024 the committee managed over 77 tonnes of waste, and the Nepal Army recovered five bodies. An estimated 40 to 50 tons of garbage still lies around the South Col. The Himalayan TimesGizmodo
16. Base Camp itself is on thinning ice. In 2022 authorities announced Base Camp would move 200 to 400 metres lower because the Khumbu Glacier beneath it is melting and thinning. A 2026 study estimated that fuel use and human urine at camp released enough heat to melt roughly 2,500 tons of ice and snow in the spring 2023 season. WikipediaWikipedia
Climbing Statistics and Fatalities
17. Less than half of the attempts succeed. Through December 2025 there were 13,737 summits, a 43% success rate, by 7,563 different people, so repeat climbers account for a large share. Alan Arnette
18. Everest is not the deadliest 8,000-metre peak. 339 people have died on it since 1921, roughly one death per 100 summits, and commercial guiding cut death rates from about 1.8 to about 0.8. Its fatality rate per attempt is lower than that of K2 or Annapurna. Alan ArnetteNepal Intrepid Treks
19. 2026 was the busiest season ever, and fairly ordinary in risk. There were a record 1,008 summits from 495 permits. 274 people summited on a single day. Five climbers died and one Sherpa is missing, the same as 2025 and below the 2023 record of eighteen. Everest deaths in 2026, the five names and the sixth man who came back alive | Travel Himalaya Nepal +2
20. Just the permit now costs $15,000. Nepal raised the spring fee from $11,000 to $15,000 on 1 September 2025, its first increase in a decade. Nepali operators charge around $45,000 for a full expedition, and Western-guided expeditions about $80,000. Trekking to the foot of the mountain costs a small fraction of that. KathmandupostAlan Arnette
What This Means for Travellers
You do not need to climb Everest to feel it. Base Camp sits about 3,500 metres below the summit, and the trek needs no technical skills, but altitude is the real challenge.
Acclimatise properly. Rest days matter more than fitness. On Global Nepal Treks' 15-day Everest Base Camp trek, guides build in rest days at Namche Bazaar and Dingboche and follow "climb high, sleep low", hiking up each acclimatisation day and sleeping lower. Guides check oxygen saturation with pulse oximeters, and trekkers should drink 3–4 litres of water a day, walk slowly and report any headache or nausea straight away.
Prepare for safety. Insurance must cover trekking to 6,000 metres and helicopter evacuation. Lukla flights are weather-dependent, so keep a buffer day. Every Global Nepal Treks guide holds a Government of Nepal trekking licence and carries a satellite phone, first-aid kit, pulse oximeter and emergency oxygen. Groups are capped at 12.
"Altitude sickness is not weakness. The trekkers who reach Base Camp happiest are the ones who tell us early when something feels wrong." — Pemba Sherpa, Global Nepal Treks
Trek responsibly. The Khumbu's rubbish problem starts on the trail. Carry a reusable bottle, take your batteries and wrappers home, and use the recycling collection points along the route. Smaller groups also mean less pressure on tea houses and trails. Global Nepal Treks' own waste practices, such as carrying out non-biodegradable waste, filtered water refills, and porter welfare and load limits.
Short on time? The Everest Helicopter Tour is a four-day luxury package with a Kala Patthar landing at 5,545 metres and breakfast at Everest View Lodge. If you want to walk in and fly out, the Everest Base Camp trek with helicopter return saves the long descent. Trekkers wanting a summit can look at Island Peak Climbing, a 6,189-metre peak in the Everest region.
Autumn (September–November) is one of the two best seasons, with spring (March–May) the other. To plan your trip, contact Global Nepal Treks.
