Definitions

See also: Michigan census statistical areas

The Detroit Urban Area, which serves as the core of the metropolitan area, ranks as the 12th most populous in the United States, with a population of 3,734,090 as of the 2010 census and an area of 1,337.16 square miles (3,463.2 km2). This urbanized area covers parts of the counties of Macomb, Oakland, and Wayne. These counties are sometimes referred to as the Detroit Tri-County Area and had a population of 3,862,888 as of the 2010 census with an area of 1,967.1 square miles (5,095 km2).

Lower Peninsula of Michigan map: MSA counties in dark yellow with additional CSA counties in light yellow

The Office of Management and Budget (OMB), a federal agency of the United States, defines the Detroit–Warren–Livonia Metropolitan Statistical Area (MSA) as the six counties of Lapeer, Livingston, Macomb, Oakland, St. Clair, and Wayne. As of the 2010 census, the MSA had a population of 4,296,250 with an area of 3,913 square miles (10,130 km2).

The nine county area designated by the OMB as the Detroit–Ann Arbor–Flint Combined Statistical Area (CSA) includes the Detroit–Warren–Livonia MSA and the three additional counties of Genesee, Monroe, and Washtenaw (which include the metropolitan areas of Flint, Monroe, and Ann Arbor, respectively). It had a population of 5,218,852 as of the 2010 census and covers an area of 5,814 square miles (15,060 km2). Lenawee County was removed from the CSA in 2000.

With the adjacent city of Windsor, Ontario and its suburbs, the combined Detroit–Windsor area has a population of about 5.7 million. When the nearby Toledo metropolitan area and its commuters are taken into account, the region constitutes a much larger population center. An estimated 46 million people live within a 300-mile (480 km) radius of Detroit proper. Metro Detroit is at the center of an emerging Great Lakes Megalopolis.