The USGS created this interesting visual which shows all of the water on our planet (including water contained in the human body) combined into a sphere for comparison purposes. The results are surprising, especially since water covers 70% of earth’s surface:
Our water sphere would have a diameter of 1,385 kilometers (about 860 miles), and span the distance from Salt Lake City, Utah to Topeka, Kansas. A sphere this far across would have a volume equal to about 1,386 million cubic kilometers (roughly 332,500,000 cubic miles)… By comparison, the Earth measures a staggering 12,256 km.
Apparently the size difference is the equivalent of comparing a basketball to a nickel.