The ocean holds about 97 percent of the Earth's water; the remaining three percent is distributed in many different places, including glaciers and ice, below the ground, in rivers and lakes, and in the atmosphere.
According to the U.S. Geological Survey, there are over 332,519,000 cubic miles of water on the planet. A cubic mile is the volume of a cube measuring one mile on each side. Of this vast volume of water, NOAA's National Geophysical Data Center estimates that 321,003,271 cubic miles is in the ocean.