The Charleston metropolitan area is the metropolitan area centered on Charleston, South Carolina. The U.S. Office of Management and Budget designates the area as the Charleston-North Charleston, SC Metropolitan Statistical Area, a metropolitan statistical area used for statistical purposes only by the United States Census Bureau and other federal agencies. The OMB defines the area as comprising Berkeley, Charleston and Dorchester counties, an area with 664,607 in the 2010 census (though a July 1, 2012 estimate placed the population at 697,439). Principal cities include Charleston, North Charleston, and Summerville. The area is commonly referred to as the Tri-County Area or the Lowcountry, though the latter term has historically referred to South Carolina coast in general.