Hawaii's Mauna Kea is taller than Everest when measured from its base
~10.2 km
Mount Everest has the highest summit above sea level, but Mauna Kea rises from the floor of the Pacific Ocean. Including its underwater portion, the Hawaiian volcano measures roughly 10.2 kilometers from base to summit. Everest is higher above sea level, while Mauna Kea has the greater total height by this particular way of measuring a mountain.