3 Mountains That Surpass Mount Everest in Height

by James Hunt

At a height of 29,029 feet (give or take), Mount Everest may appear to be the highest peak on Earth. However, the title of the 'tallest mountain' is determined by how measurements are taken. Here are three contenders vying for the title.

Mauna Kea

The dormant volcano Mauna Kea in Hawaii is one of the peaks that could arguably be considered taller than Everest—if the title of 'tallest' is determined by a technicality.

The summit of Mauna Kea is certainly not higher than Everest’s. At 13,796 feet above sea level, it’s less than half the height of Everest. So why does it challenge the title of the tallest mountain? The answer lies in the phrase: 'above sea level.'

If you disregard the ocean around Mauna Kea and measure the mountain from its underwater base—a measurement called 'dry prominence'—Mauna Kea actually exceeds Everest by nearly 1,640 feet. From the point where Mauna Kea rises from the ocean crust, the total height reaches around 30,610 feet. Since Everest isn’t submerged, its dry prominence is the same as its height above sea level. But if both mountains were placed side by side on a flat surface, Mauna Kea would undoubtedly be the taller of the two.

Several factors contribute to Mauna Kea’s height surpassing that of a mountain formed above sea level, with the primary reasons being related to the crust beneath it. Oceanic crust is denser and less prone to sag compared to continental crust. It is also much thinner, measuring only 4 to 6 miles thick, as opposed to the 15 to 43 miles of continental crust.

In contrast, Mount Everest sits atop the already heavy continental crust. Because water is far less dense than rock, the oceanic crust beneath Mauna Kea carries less weight below sea level than the continental crust supporting Everest. As a result, it can sustain a greater prominence than would be possible above sea level.

Olympus Mons

If Mauna Kea’s height only surpasses Everest due to a technicality, then perhaps Olympus Mons makes a stronger case for the title. This dormant volcano stands about three times taller than Mount Everest, with no sea water to complicate the starting point for measuring its height. However, if you’re an aspiring mountaineer looking for a challenge, you might have to wait a bit: Olympus Mons is located on Mars.

Olympus Mons isn’t just the largest dormant volcano on Mars; it’s the largest known volcano in the entire solar system. It rises approximately 13 miles above the local terrain and Mars’s geodetic datum (its version of sea level), extending over 16 miles above the plains of Mars. At its base, it spans an area roughly the size of Arizona. So, how did it get so enormous?

Perhaps it’s due to reduced gravity, less weathering, or simply a stroke of luck. The most probable reason, though, is that the Martian crust isn’t divided into tectonic plates like Earth’s, resulting in a much more stable geological environment.

On Earth, when a volcano forms, the shifting of tectonic plates causes it to move until it no longer receives pressurized magma, eventually halting its eruptions. On Mars, Olympus Mons stayed in one spot for millions of years, growing with each eruption until the Martian core cooled enough to stop volcanic activity.

For context, Mount Everest has been gradually growing for around 60 million years due to the collision of the Indian and Eurasian tectonic plates. The eruptions that formed Olympus Mons date back as far as 350 million years, with the youngest sections indicating eruptions as recent as 2 million years ago. In geological terms, that’s practically yesterday.

Chimborazo

On Earth, there’s one final contender for Everest’s title: Mount Chimborazo in Ecuador. While Everest certainly claims the title of the highest peak on Earth, and Mauna Kea arguably holds the title of the tallest, Chimborazo is the most prominent—it extends the farthest from the center of the Earth.

How is this possible? It all comes down to the shape of the Earth. Chimborazo stands at 20,564 feet, but its proximity to the equator is key. Earth is slightly squished, being wider around the equator than at the poles, which makes Chimborazo’s peak the farthest point from the Earth’s core that remains connected to the crust. And this is not by a small margin—Chimborazo’s peak is 20,000 feet farther from the core than Everest’s, nearly two-thirds of Everest’s height. While Everest is still the highest point above sea level, that is influenced by the equatorial bulge as well.

Ultimately, Mount Everest will always hold the title of the highest point on Earth, ensuring its place in the aspirations of those daring enough to take on nature. But the next time someone claims that Everest is the tallest mountain possible, you'll have the perfect response: while moving mountains is impossible, shifting the goalposts is surprisingly easy.