If you think Mount Everest is the tallest mountain on Earth, you may not be 100% right. It all comes down to perspective. To understand height, whether you’re looking at mountain ranges or in the cockpit of a plane, you have to understand that altitude and elevation are two different things.
Altitude and elevation are different ways of looking at height. Height is a measure of vertical distance. We often refer to height when we talk about how tall someone is, but it can also refer to the vertical position of something, like a plane in the air.
Altitude refers to the vertical distance measured from an object to the Earth’s surface. When it comes to mountains, the altitude usually measures the mountain’s peak to its base.
In flight, altitude gets switched with the definition for elevation. Specifically, true altitude refers to the vertical distance between a plane and a mean sea level. However, aviation also has other forms of altitude, not all of which necessarily pertain to height.
Elevation measures the distance between an object and the standard mean sea level. The sea level can potentially exist above or below the base of a mountain.
The sea level is constantly fluctuating and can vary at different points of the world. This is why experts have had to calculate a standard mean sea level, which is the average height of the entire ocean surface.
The National Oceanic and Atmospheric Administration has created a model of the Earth that factors in the mean sea level. This model is known as the geoid.
Going just by elevation, Everest is indeed the tallest mountain on Earth. The most recent measurement has it at 29,031.69 feet above mean sea level.
Mauna Kea, an inactive volcano in Hawaii, has a peak that is just 13,802 feet above sea level. However, much of Mauna Kea is hidden below sea level. From base to peak, Mauna Kea measures 33,497 feet, making it the tallest mountain by altitude.
Most people, even geography experts, mix up altitude and elevation, and the different forms of altitude in flight only make this even more confusing. Genuinely, if you say either in everyday conversation, most people will know you’re talking about an object’s height, but if you’re talking about flight, stick with altitude.