It’s not in dispute that Mount Everest is the highest mountain in the world with the peak of the mountain at 8,848m (29,029ft) above sea level. However, the base of Mount Everest itself is already very high above sea level at about 5,200 m (17,000 ft). The height of Everest is roughly 3,700m (12,000 ft) from its base to its peak.

There are a number of other mountains on earth that are taller than this.

To describe Mt. Everest as the tallest mountain on earth is equivalent to declaring that the tallest person on earth is any person who is standing at the top of Mt. Everest. We don’t declare a 3 story building in Denver as being taller than the Freedom Tower in New York or the Willis (formerly Sears) Tower in Chicago just because it is further above sea level.

So what is the tallest mountain?

Mauna Kea in Hawaii is the mountain with the greatest distance from its base to its summit.

You may question whether the part of the mountain under sea level counts towards its height. You’d be hard-pressed to find a definition of a mountain that would exclude any part of that mountain that may be underwater, but let’s explore that.

What is the tallest land-based mountain in the world?

The answer to that question is the mountain formerly known as Mt. McKinley – Denali in Alaska. Denali is about 5,500 m (18,000 feet) tall from its base, rising to a peak that is about 6,200 m (20,300 ft) above sea level.

Other mountain facts

• The highest mountain above the center of the earth is Chimborazo in Ecuador at a peak elevation of 6,310 m (20,703 ft).
• The tallest mountain in our solar system is the Rheasilvia central peak on the asteroid Vestia with a height of about 23km.
• Most geologists classify a mountain as a landform that rises at least 1,000 feet (300 meters) or more above its surrounding area.

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