Not to be confused with Three One Third
313 is a North American Numbering Plan telephone area code that serves Detroit and most of its surrounding suburbs in Wayne County, Michigan. It includes the Hamtramck and Highland Park enclave cities, as well as Allen Park, Dearborn, Dearborn Heights, Ecorse, Inkster, Melvindale, the Grosse Pointe communities, Lincoln Park, Redford, River Rouge, and Taylor north of Goddard Road and east of Holland Road.
Area codes are used by rappers and inner-city youths to acknowledge where someone comes from.
Originally, area code 313 served the entire southeastern quadrant of Michigan, including Metro Detroit, Flint, and the southern part of Michigan's "Thumb" On December 1, 1993, the northern portion of the area was separated with the new area code 810. The remaining 313 area was reduced to its current size on December 13, 1997, when the western portion received area code 734.
The Detroit area code, 313, is frequently mentioned in Eminem's music due to the city's setting in the film 8 Mile. In the film, B–Rabbit and his friends call their group "three one third" a reference to the 313 area code.