Mount Everest is 29,032 feet tall. For you metric types that’s a whopping 8,849 meters! Mount Everest is the tallest mountain on planet earth. Interestingly, while the peak of Mount Everest is the highest point above sea level on our planet, it is NOT the tallest mountain when you measure from base-to-peak. That honor goes to Mauna Kea–a volcanic island in Hawaii which is roughly 33,400 feet (10,200 meters) tall. We don’t often talk about Mauna Kea in “world’s tallest mountain” discussions however because about 40% of this volcano’s height is underwater.