Mauna Loa is the largest subaerial and second largest overall volcano in the world (behind Tamu Massif), covering a land area of and spans a maximum width of . Consisting of approximately of solid rock, it makes up more than half of the surface area of the island of Hawaiʻi. Combining the volcano's extensive submarine flanks ( to the sea floor) and subaerial height, Mauna Loa rises from base to summit, greater than the elevation of Mount Everest from sea level to its summit. In addition, much of the mountain is invisible even underwater: its mass depresses the crust beneath it by another , in the shape of an inverse mountain, meaning the total height of Mauna Loa from the start of its eruptive history is about .