This picture shows the size of a sphere that would contain all of Earth’s water in comparison to the size of the Earth. The blue sphere has a diameter of about 860 miles (about 1,385 kilometers) , with a volume of about 332,500,000 cubic miles (1,386,000,000 cubic kilometers). The sphere includes all the water in the oceans, seas, ice caps, lakes and rivers as well as groundwater, atmospheric water, and even the water in you, your dog, and your tomato plant.
Credit: Illustration by Jack Cook, Woods Hole Oceanographic Institution; USGS. (web-sourced at ga.water.usgs.gov/edu/earthhowmuch.html)
Data source: Igor Shiklomanov’s chapter “World fresh water resources” in Peter H. Gleick (editor), 1993, Water in Crisis: A Guide to the World’s Fresh Water Resources (Oxford University Press, New York).