Mount Everest Is Not the Tallest Mountain — Mauna Kea in Hawaii Beats It by Two Miles

Most people know that Mount Everest is the highest mountain on Earth — its summit is 8,849 meters above sea level. What most people don't know is that "highest above sea level" is just one way to measure a mountain.

If you measure mountains from their base, the answer is very different.

Mauna Kea: The Real Tallest Mountain

Mauna Kea, a dormant shield volcano on the Big Island of Hawaii, rises only 4,207 meters above sea level. But its base sits on the ocean floor, 5,995 meters below the surface. The total height of Mauna Kea, from base to summit, is 10,205 meters — about 1,355 meters taller than Everest.

Other Ways to Measure

• Highest above sea level: Mt. Everest (8,849 m)
• Tallest from base to peak: Mauna Kea (10,205 m)
• Farthest from Earth's center: Mt. Chimborazo, Ecuador. Earth bulges slightly at the equator, so Chimborazo's summit (~6,310 m above sea level) is actually 2,168 meters farther from Earth's center than Everest's summit
• Highest unclimbed: Gangkhar Puensum (7,570 m) in Bhutan, off-limits to climbers due to local religious beliefs

The Real Tallest Object

If we extend the concept to any object on Earth's surface — including volcanoes — Olympus Mons on Mars still wins at 21.9 km tall, three times Everest. But staying on Earth, Mauna Kea is the height champion.

Why It Matters

Astronomers love Mauna Kea. Its high elevation puts the peak above 40% of Earth's atmosphere. Its dry, stable, isolated location makes it one of the best astronomical observation sites on Earth. The summit hosts 13 of the world's largest telescopes, including the Keck Observatory.

Most "highest mountain" lists ignore base-to-peak height because we generally measure terrestrial elevation against sea level. But for a mountaineer, both definitions matter. The next time you see a Hawaii postcard, remember: you are looking at Earth's tallest mountain.