Cook County · Illinois
Chicago, IL area codes and time zone
Quick answer
Chicago is served by area codes 219, 224, 331, 630, 708, 847, keeps CST time (GMT-6), and sits in county FIPS 17031.
- Area codes
- 219 · 224 · 331 · 630 · 708 · 847Within 25 miles of the city centre
- Time zone
- CSTAmerica/Chicago
- UTC offset
- GMT-6CDT in summer (UTCGMT-5)
- County FIPS
- 17031Cook County
Dialling from and to Chicago
What this means when you pick up the phone.
Because more than one code covers this area, ten-digit dialling applies for local calls: area code plus number, every time. From abroad, dial +1 then the ten digits.
How Chicago came to have several area codes
Why one city can carry several codes.
Area codes are assigned to geography, then exhausted as demand grows. Chicago — population about 2,664k — is covered by codes 219, 224, 331, 630, 708, 847, drawn from within 25 miles of the city centre. Because these 6 codes serve the same footprint, they are overlays: the number pool ran low and a new code was layered on top rather than splitting the city apart. All ten digits are required for every local call.
More Chicago data
Other Chicago datasets on this site.
- Chicago population and income
- Chicago sales tax rate
- Chicago property tax
- Chicago cost of living
- Chicago home values and rent
- Chicago crime rates
- Chicago public schools
- Chicago weather normals
- Chicago commute times
Statewide: Illinois cities · Illinois ZIP codes · Illinois sales tax · Illinois counties