The U.S. Shoreline Is More Than 95,000 Miles Long

How long is the edge of a country? It depends on how closely you measure. NOAA’s official value for the total length of the U.S. shoreline is 153,646 kilometers, or 95,471 miles. NOAA is open about the limits of that figure. There is no reference that designates one specific shoreline as the legal shoreline, so numbers for the length of the U.S. shoreline can vary depending on how the shoreline is defined. The official calculation uses measurements taken in 1930 to 1940 and in 1970. It includes the shorelines of the outer coast, offshore islands, sounds, bays, rivers and creeks, up to the head of the tidewater or to a point where tidal waters narrow to a width of 100 feet. The Great Lakes, measured in 1970, and outlying U.S. territories are included as well.