Trekking
How Everest's Height Was Measured
Everest's official height has been updated multiple times as surveying technology improved. The story behind measuring the world's tallest mountain spans 170 years of science and determination.
Measuring the height of a mountain hidden behind hundreds of kilometres of foothills requires extraordinary ingenuity.
Overview
The Great Trigonometrical Survey of India first calculated Everest's height in 1856, arriving at 8,840m — remarkably close to today's figure. The mountain was designated Peak XV and later named after Sir George Everest, the survey's former Surveyor General. The 1999 GPS survey revised the figure to 8,850m. In 2020, a joint China-Nepal survey established the current official height of 8,848.86m, measured to the rock summit rather than the snow cap. Surveyors use trigonometric calculations, GPS satellites, and now precise geoid models to account for gravitational variations. The difference between rock and snow measurements can be several metres — the 2020 survey settled the debate by declaring the rock height canonical. Nepal and China jointly announced the result, ending decades of competing claims. Getting to the survey site to place instruments at the summit requires full mountaineering expeditions. Sajilo can arrange your Kathmandu logistics for any Everest region journey.
FAQ
Why did the height change in 2020? Improved GPS technology and geoid models allowed more precise measurement. The 2020 figure (8,848.86m) replaced the 1954 Survey of India result of 8,848m.
Is the height measured to rock or snow? The current official height is measured to the rock summit beneath the snow cap, unlike earlier measurements that included snow.
Planning this trip? 🎒
Don't stress about transport or guides. Sajilo offers verified cabs, luxury tourist buses, and expert guides across Nepal.
