Its surface area is approximately 4·π (4000 mi)<sup>2</sup> = 200 million square miles (510 million km<sup>2</sup>). It has been said that Earth should really be called "water", as the larger part of it—about 70%—is covered by water. In fact, the Pacific and Indian oceans alone cover about half of the Earth's surface. | Its surface area is approximately 4·π (4000 mi)<sup>2</sup> = 200 million square miles (510 million km<sup>2</sup>). It has been said that Earth should really be called "water", as the larger part of it—about 70%—is covered by water. In fact, the Pacific and Indian oceans alone cover about half of the Earth's surface. |