What is the name of the biggest mountain in the world?
You would think that this would be an easy question to answer, but it actually takes a little thought. While Mount Everest is generally celebrated as the world's tallest peak, it really depends on how you look at it.
Mount Everest is 29,029 feet above sea level. From that standpoint it is the world's tallest mountain. It is also the most famous mountain. Annual treks to the top often make the news, and more than 400 climbers have died in their efforts to conquer the peak.
However, there is another mountain in Hawaii called Mauna Kea. Mauna Kea is an island mountain that stands 13,796 feet above sea level. Mount Everest is over 15,000 feet higher above sea level. But, since Mauna Kea is a mountain in the ocean, you have to measure its height from the ocean floor. When you do that, Mauna Kea is actually about 33,000 feet tall, which makes it about 13.6% taller than Everest.
Since Mauna Kea is mostly underwater, we don't hear too much about it—nobody tries to scale underwater mountains; it wouldn't be possible, so it loses the romantic, adventurous appeal of Everest.