The Answer:

About 70.8% of the Earth's surface is covered by water. Here's the breakdown on land and water versus total area.

• Total area: 510.072 million sq km (196.93 million sq mi.).
• Land area: 148.94 million sq km (57.50 sq mi.).
• Water area: 361.132 million sq km (139.43 sq mi.).
• Comparative area: land area about 15 times the size of the United States.

For further statistics, see our Profile of the World.

—The Editors