The contiguous United States are the 48 adjoining U.S. states on the continent of North America that are south of Canada and north of Mexico, plus the District of Columbia. The term excludes the states of Alaska and Hawaii, and all off-shore U.S. territories and possessions, such as Puerto Rico.
Together, the 48 contiguous states and D.C. occupy a combined area of 3,119,884.69 square miles (8,080,464.3 km2), which is 1.58% of the total surface area of the Earth. Of this, 2,959,064.44 square miles (7,663,941.7 km2) is land, composing 83.65% of U.S. land area. Officially, 160,820.25 square miles (416,522.5 km2) is water area, composing 62.66% of the nation's water area. The 2010 census population was 306,675,006, composing 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.