Where is the largest volcano in the world?

Mauna Loa on the Big Island of Hawaii is the largest active volcano on Earth, a broad shield volcano with a volume of about 75,000 cubic kilometres. It rises 4,169 metres above sea level, but measured from its base on the ocean floor it is over 9,000 metres tall — taller than Mount Everest. Its gently sloping shape comes from the runny basaltic lava it erupts, which flows long distances rather than building a steep cone. The even larger Tamu Massif, an underwater volcano in the Pacific, was once considered the biggest single volcano on Earth, though later research suggested it may be a different type of feature.