What is the
tallest mountain
on earth?

Mount Everest is, of course, considered the tallest mountain on Earth, with a summit elevation of 29,032 feet above sea level. But how important is sea level, really?

When we take a closer look, we see the north face of Everest rises some 9,000 feet above the Rongbuk Glacier.

On the other side, the summit looms even more modestly above the Khumbu Glacier—just 7,500 feet.

Because it tops out so high above a distant coast, Everest gets all the glory: It’s the tallest peak, the roof of the world, Earth’s most impressive mountain. But what if it’s none of those things?

Our understanding of a mountain’s scale—what height even means!—has long been subject to alternate ways of thinking. And a whole new metric, called jut, has rekindled debate among mountaineers, hikers, and geographers over what makes a mountain great.

The truth is, Everest’s supremacy is shaky. Change how you measure and you’ll find challengers around the world for the title of tallest mountain.

Welcome to Ecuador, where the dormant volcano called Chimborazo rises 20,561 feet above sea level.

That’s nearly 9,000 feet “below” Everest.

But let’s measure from a different starting point: the center of the Earth.

Chimborazo’s summit actually soars 7,001 feet higher above the Earth’s center than Everest’s. How can this be?

It’s because our planet isn’t a perfect sphere—centrifugal force from its rotation creates a bulge at the Equator. Chimborazo sticks “farther out.”

Imagine Everest is a person with her feet on the ground while Chimborazo is standing on a chair. Whose head is higher?

But let’s take away the chair. What if we measure a mountain as we really measure a person, from the bottom to the top?

Meet another dormant volcano: Mauna Kea, on the Big Island of Hawaii. By height above sea level, it’s not even half an Everest.

We can measure it instead from its base, but first we’ll need to decide where that is. Where does Mauna Kea “start”? At the tree line? At the coast?

In fact, the mountain arguably begins its rise far beneath the waves: nearly 70 miles away, on the seafloor of the Northeast Pacific Basin. Measure it from that base and it’s 32,100 feet high—a few thousand feet taller than Everest.

Measuring a mountain from base to peak is tricky, since there’s no standard way of designating a mountain’s base. It’s a subjective measure. But there are ways to calculate a mountain’s rise that don’t require a judgment call.

You’re looking at the very top of the Andes. The summit of Aconcagua, in Argentina, is the highest point above sea level outside of Asia.

It’s also the world’s tallest mountain by topographic prominence, a measurement created by mountaineers in the 1980s to assess a mountain’s height relative to its surroundings.

It’s a measure that favors isolated mountains and summits that tower over their neighbors. That’s Aconcagua, the world’s most prominent peak. You’d have to travel 10,000 miles to Pakistan’s Hindu Kush to find the closest higher peak.

Unless you count Everest. Because prominence measures how far down from a peak you’d have to walk before starting to climb a higher one—and Everest has no “higher one,” so it’s disqualified.

You can determine a peak’s prominence by reading a topographic map. But more recently invented mountain measures require some computing power.

They call Nanga Parbat the “killer mountain.” It’s often considered the hardest to climb among the 14 peaks known as the eight-thousanders (more than 8,000 meters, or 26,657 feet, above sea level).

It’s also the world’s number one peak for what’s called omnidirectional relief and steepness—or ORS, for short. ORS is a mathematically complex measure invented in 2002 by a mathematician-and-climber duo.

It considers the relief of all the terrain surrounding a summit and how steeply it falls away, then spits out a number quantifying how dramatically the summit stands out.

ORS relies on a complicated formula, but it’s maybe best understood as measuring how visually imposing a peak looks from all sides.

But say you cared most how big a mountain feels while looking up at it. A brand-new metric, called jut—invented by a Yale undergrad—gauges how impressively a mountain rises (or “juts” upward) from any given viewpoint.

Annapurna, at the southern edge of the Himalaya, juts up more spectacularly than any other peak. According to the equation behind jut—which factors in the vertical rise and angle of slope between two points—it has the world’s single most dramatic mountain face.

Everest’s jut, by contrast, is only two-thirds as high as Annapurna’s. In fact, by this measure, Everest ranks as only the world’s 46th most impressive mountain.

One neat thing about jut? Using its formula, geospatial software can determine a mountain’s theoretically ideal viewpoint—and this spot is designated as a mountain’s base.

Even if the peak above Annapurna’s southwest face, called Annapurna Fang, isn’t the world’s tallest, its high jut score means that anyone standing at that base would get the world’s most sensational impression of tallness.

Using digital heat maps that show the jut of mountains around the globe, hikers and climbers are discovering little-heralded, even nameless peaks worth trekking to.

It goes to show how rethinking the pecking order of the planet’s mightiest mountains can change travelers’ sightseeing plans, point peak baggers in new directions, and of course, reallocate bragging rights.

Knowing what you know now, which mountain do you think deserves the title of tallest mountain in the world?