Cook ZIP codes — Cook County, Illinois

Cook County is a major city in Illinois, with 5,185,812 residents counted in the Census American Community Survey 2019-2023 ACS 5-year estimates. The median age here is 37.8 years against 39.1 nationally, a slightly younger profile than the country as a whole. At this size the Census also publishes one-year estimates; the five-year values used here are steadier and let you compare against smaller neighbours on the same basis.

Households in Cook County earn a median of $81,797 a year, 4.1% above the national figure of $78,538. This figure covers the household, not the worker: two people on ordinary wages at one address outrank a single professional in the same table. Poverty reaches 13.3% of residents here, above the 12.4% national rate.

The typical owner-occupied home in Cook County is valued at $305,200, essentially level with the national figure, while median gross rent runs $1,381 a month, 1.8% below the national figure, or roughly $16,572 across a full year. A household on the local median income would put about 20.3% of gross pay toward that rent against the federal 30% cost-burden threshold, so renting here is within the standard affordability guideline. The home-price-to-income ratio works out to 3.7×, against roughly 3.9× nationally, so buying is easier here than in the average US market. 57.5% of occupied homes are owner-occupied versus 65% nationally, so the market leans more heavily on renters. The rent line includes utilities paid by the tenant, a definition worth remembering when comparing it against a landlord's quoted rate.

Median income runs above the national figure while poverty also runs above it — a split distribution, not a uniformly comfortable place. Averages hide that; the two numbers together do not.

Every value on this page is published directly by the Census for this area — nothing is modelled or interpolated. Small-area estimates still carry wider margins of error than state or national figures, so check the linked ACS tables before relying on them for lending, appraisal or legal work.