Lake Forest, IL population, income and ZIP codes

Lake Forest city is a mid-size town in Illinois, with 19,190 residents counted in the Census American Community Survey 2019-2023 ACS 5-year estimates, which places it #128 of 1,462 ranked by population — larger than 91% of them. The median age here is 46.1 years against 39.1 nationally, a markedly older profile that usually tracks retirees staying put and younger households leaving for work. 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 Lake Forest city earn a median of $228,120 a year, 190.5% above the national figure of $78,538 and 207% above the $74,244 median for the 698 Illinois cities we cover. 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 4% of residents here, less than half the 12.4% national rate.

The typical owner-occupied home in Lake Forest city is valued at $909,800, 199.9% above the national figure and 408% above the $179,100 peer median, while median gross rent runs $2,120 a month, 50.8% above the national figure, or roughly $25,440 across a full year. A household on the local median income would put about 11.2% 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 4×, against roughly 3.9× nationally, so buying is harder here than in the average US market. 89.3% of occupied homes are owner-occupied versus 65% nationally, an owner-dominated market where rental listings are scarce and rent medians rest on a thin sample. Gross rent folds in the utilities a tenant pays separately, so it is closer to the real monthly outlay than a headline rent figure.

No figure on this page is estimated by us; each one comes straight from the published ACS tables for this area. 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.