Geographic Regions and Area Codes in Chicago, Illinois

Chicago, Illinois, is a major urban center located in the northeastern part of the state, along the southwestern shores of Lake Michigan. The city covers an area of approximately 234 square miles and extends inland to meet its suburbs. The greater Chicagoland area includes parts of Indiana and Wisconsin and encompasses several counties such as Cook, DuPage, Kane, Kendall, Lake, McHenry, and Will.

Chicago is divided into several regions, each with its own unique characteristics and area codes:

  • Central City Area: Covered by the 312 area code, this region includes the Chicago Loop and the Near North Side.
  • Geographical Area Except Downtown: Covered by the 773 area code, this region encompasses most of the city's geographical area.
  • Overlay Area: The 872 area code overlays both the 312 and 773 area codes, providing additional numbering options.

These area codes are essential for businesses to understand as they plan their operations and customer interactions in Chicago.