The continental United States commonly refers to the 48 contiguous states located on the central part of the North American continent, plus the District of Columbia, and so does not include Alaska and Hawaii. continental, adj., "being the part of the United States on the North American continent; also : being the part of the United States comprising the lower 48 states" "CONUS" seems to be used primarily by the American military and the Federal government and those doing business with them.

• 'CONUS - "Continental United States." CONUS refers to the 48 contiguous states.' U.S. Navy Style Guide
• "CONUS move: A PCS move where both the current and new duty stations are defined as being within the continental United States (CONUS). CONUS includes only the 48 contiguous states, not Alaska and Hawaii." Military Assistance Program glossary

Because Alaska is also on the North American continent, the term, if interpreted literally, would also include that state, so the term is sometimes qualified with the explicit inclusion or exclusion of Alaska to resolve any ambiguity. This ambiguity existed long before Alaska became a state in 1959.

Some other terms which are equivalent in common usage are:

• contiguous United States
• coterminous (or conterminous) United States
• the lower 48
• CONUS

The 48 states and D.C. together have an area of 3,119,686 square miles (8,079,461 km²).