The state of Illinois covers 37,064,960 acres, or 57,914 square miles, according to the 2010 U.S. Census. Just over 36.5 million acres of the area are land, and bodies of water make up 1.5 million acres.
These numbers make Illinois the 25th largest state as measured by total area. The state is 4.1 percent water and 95.9 percent land, as reported by the U.S. Geological Survey. Because it is landlocked, Illinois has no coastal waters, so the remainder of the state's water area not covered by the southwest portion of Lake Michigan comes from its rivers, streams and other smaller lakes.