Mauna Loa in Hawaii is indeed the world's largest volcano by volume and area. It rises about 9 km (5.6 miles) from the ocean floor to its summit, with a total height of over 17 km (10.6 miles) from base to peak - taller than Mount Everest when measured from base. Mauna Loa covers about 5,271 sq km (2,035 sq miles) and has an estimated volume of 80,000 cubic km. While some volcanoes like Olympus Mons on Mars are larger, Mauna Loa is the largest on Earth. Mount Baker, Cold Bay, and Stromboli are all significantly smaller in size and volume.