The contiguous United States or officially the conterminous United States consists of the 48 adjoining U.S. states (plus the District of Columbia) on the continent of North America. The terms exclude the non-contiguous states of Alaska and Hawaii, and all other off-shore insular areas, such as American Samoa, U.S. Virgin Islands, Northern Mariana Islands, Guam and Puerto Rico. These differ from the related term continental United States, which includes Alaska (also on the North American continent but separated from the 48 states by British Columbia, Canada) but excludes the Hawaiian Islands and unincorporated U.S. territories in the Caribbean and the Pacific.
The greatest distance (on a Great-circle route) entirely within the 48 contiguous states is 2,802 miles (4,509 km) between Florida and the State of Washington; the greatest north–south line is 1,650 miles (2,660 km).
Together, the 48 contiguous states and the District of Columbia occupy an area of 3,119,884.69 square miles (8,080,464.3 km2). Of this area, 2,959,064.44 square miles (7,663,941.7 km2) is contiguous land, composing 83.65% of total U.S. land area, similar to the area of Australia. Officially, 160,820.25 square miles (416,522.5 km2) of the contiguous United States is water area, composing 62.66% of the nation's total water area.
The contiguous United States would be placed 5th in the list of sovereign states and dependencies by area; the total area of the country, including Alaska and Hawaii, ranks third. In land area only, the country ranks fourth, ahead of Brazil but behind Russia, Canada and China. Brazil is 431,000 square kilometers (166,000 sq mi) larger than the contiguous United States, but smaller than the entire United States, while Russia, Canada, and China are the only three countries larger than both. The 2010 census population of this area was 306,675,006, comprising 99.33% of the nation's population, and a density of 103.639 inhabitants/sq mi (40.015/km2), compared to 87.264/sq mi (33.692/km2) for the nation as a whole.