313 Area Code: Detroit, Michigan

Detroit is the primary city of the 313 area code, the long-running designation for the city itself and the immediately surrounding communities. Detroit sits along the Detroit River across from Windsor, Ontario, on a stretch of the river that connects Lake St. Clair with Lake Erie. The city's working economy has been shaped over a century by the automobile industry — Ford, GM, and Stellantis (the former Chrysler) all maintain substantial operations in the metro — and the surrounding rebuilt downtown reflects a long reorientation alongside the industry's reshaping. The 313 footprint covers the city of Detroit, Hamtramck, Highland Park, Dearborn, and the immediately surrounding inner suburbs.

Records linked to 313 numbers in the directory often include other Michigan cities — Ann Arbor, Flint, Grand Rapids, and Kalamazoo among them. None of those are inside the 313 footprint. The pattern reflects standard public-record dynamics, with phone numbers porting across Michigan and addresses linked across multiple cities. The directory currently documents 614 distinct prefixes within 313 in detail, a working subset of the prefix population the code carries.

Detroit's home values come in dramatically below the US median, with median household income running well below the national figure — a reading shaped by the city's long-running fiscal and population transitions through the late twentieth and early twenty-first centuries. The city's median age sits in the mid-thirties (a few years under the US reading), and population places Detroit among the larger cities in the Midwest, the historical anchor of an extensive metropolitan region in southeast Michigan.