The Pacific Ocean is the world's largest ocean. With an area of 63.8 million square miles, or 165.25 million square kilometers, it covers around a third of the Earth's total area, more than all the land in the world.
The second largest ocean, the Atlantic Ocean, has an area of 31.8 million square miles, or 82.4 million square kilometers, roughly half of the size of the Pacific.
The Pacific Ocean received its name from the explorer Ferdinand Magellan, who was surprised at how calm its waters were compared to the difficult seas he encountered sailing around Cape Horn, at the southern tip of South America. He called it the "Mar Pacifico," which in Spanish means "peaceful ocean."