Grundy ZIP codes — Grundy County, Illinois

Grundy County is a small city in Illinois, with 52,920 residents counted in the Census American Community Survey 2019-2023 ACS 5-year estimates. The median age here is 38.6 years against 39.1 nationally, a slightly younger profile than the country as a whole. Places under 65,000 residents only appear in the five-year release, never the one-year file, so these values pool sixty months of responses and lag the current year by design.

Households in Grundy County earn a median of $93,060 a year, 18.5% above the national figure of $78,538. Household income here is measured before tax and pooled across everyone at the address, which is why it reads higher than typical individual earnings in the same area. Poverty reaches 6.3% of residents here, below the 12.4% national rate.

The typical owner-occupied home in Grundy County is valued at $259,200, 14.6% below the national figure, while median gross rent runs $1,137 a month, 19.1% below the national figure, or roughly $13,644 across a full year. A household on the local median income would put about 14.7% of gross pay toward that rent against the federal 30% cost-burden threshold, so renting here is cheap relative to what people here earn. The home-price-to-income ratio works out to 2.8×, against roughly 3.9× nationally, so buying is easier here than in the average US market. 75.8% of occupied homes are owner-occupied versus 65% nationally, so the market leans toward owners. The rent line includes utilities paid by the tenant, a definition worth remembering when comparing it against a landlord's quoted rate.

All values below were released by the Census for this exact geography, with no gap-filling on our side. 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.