What is the world's tallest mountain above sea level?

Mount Everest is the world's tallest mountain above sea level.

Its summit is 8,848.86 metres above sea level according to the official Nepal–China measurement announced in 2020. Everest stands in the Himalayas on the border between Nepal and China's Tibet Autonomous Region.

The mountain is called Sagarmatha in Nepal and Qomolangma in Tibet. The English name honours George Everest, a former Surveyor General of India, although he did not personally survey the peak.

Everest is not the tallest mountain when measured from base to summit: Mauna Kea in Hawaii is taller by that measure because much of it lies beneath the Pacific Ocean. K2 is the world's second-highest mountain above sea level.