The contiguous United States (officially the conterminous United States) consists of the 48 adjoining U.S. states and the District of Columbia of the United States in central North America.[1][2] The term excludes the only two non-contiguous states, which are Alaska and Hawaii (they are also the last two states to be admitted to the Union), and all other offshore insular areas, such as the U.S. territories of American Samoa, Guam, the Northern Mariana Islands, Puerto Rico, and the U.S. Virgin Islands.[3][4] The colloquial term "Lower 48"[5] is also used, especially in relation to Alaska.
The related but distinct term continental United States includes Alaska, which is also on North America, but separated from the 48 states by British Columbia in Canada, but excludes Hawaii and all the insular areas in the Caribbean and the Pacific.[1][6]
The greatest distance (on a great-circle route) entirely within the contiguous U.S. is 2,802 miles (4,509 km), coast-to-coast between Florida and the State of Washington;[7] the greatest north–south line is 1,650 miles (2,660 km).[8] The contiguous United States occupies 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 actual land, composing 83.65 percent of the country's total land area, and is comparable in size to the area of Australia.[9] Officially, 160,820.25 square miles (416,522.5 km2) of the contiguous United States is water area, composing 62.66 percent of the nation's total water area.
The contiguous United States, if it were a country, would be fifth on the list of countries and dependencies by area, behind Russia, Canada, China, and Brazil. However, the total area of the United States, including Alaska and Hawaii, ranks third or fourth. Brazil is 431,000 square kilometers (166,000 sq mi) larger than the contiguous United States, but smaller than the entire United States including Alaska, Hawaii and overseas territories. The 2020 U.S. census population of the area was 328,571,074, comprising 99.13 percent of the nation's total population, and a density of 111.04 inhabitants/sq mi (42.872/km2), compared to 93.844/sq mi (36.233/km2) for the nation as a whole.[10]
Contiguous United States: The 48 adjoining states and the District of Columbia.
The continental United States includes Alaska. [...] In Alaska context, lower forty-eight or lower 48 may be used. Do not hyphenate lower 48 as an adjective. The term outside may be put in quotes on first reference if ambiguous. To distinguish the 48 states from the 49 or 50, use contiguous or conterminous.