Lenzburg, Illinois Demographics & Population 2026

A note before these figures: with a population of 428, Lenzburg's ACS estimates come from a small number of survey responses and carry wide margins of error. Individual percentages below — particularly rates that round to 0% or 100% — are approximations, not precise measurements. See data.census.gov for the published margins of error.

Population Overview

Lenzburg is a small community located in Illinois, within St. Clair County. The total population is 428. It ranks as the 983rd most populous out of 1,445 Census-designated places in Illinois.

Age Demographics

The median age in Lenzburg is 32.0 years. This is 18% lower than the state median of 39.0 years. With 31.8% of the population under 18, Lenzburg has a notably young demographic profile, suggesting a family-oriented community.

Economy, Income & Housing

The median household income in Lenzburg is $42,656. This is 49% lower than the state median of $83,390. It is also 47% lower than the national median of $80,734. The poverty rate stands at 21.6%. This is 83% higher than the state poverty rate of 11.8%. With more than one in five residents living below the poverty line, economic hardship is a significant challenge for the community. The unemployment rate is 5.5%. This is 6% lower than the state rate of 5.8%. The median home value is $77,900. Housing costs are 70% lower than the state median of $263,300. With a home-value-to-income ratio of just 1.8x, Lenzburg is one of the most affordable housing markets in the area. 63.6% of occupied housing units are owner-occupied. This homeownership rate is 5% lower than the state average of 67.1%.

Race & Ethnicity

Lenzburg has a predominantly White (non-Hispanic) population, comprising 92.5% of all residents. Hispanic or Latino residents account for 3.0%. The White (non-Hispanic) population is significantly higher than the state average (92.5% vs 58.1%). The Black or African American population (0.2%) is well below the state average of 13.3%. The Hispanic or Latino population (3.0%) is well below the state average of 18.8%.

Education

14.2% of residents aged 25 and older hold a bachelor's degree or higher. This is 62% lower than the state rate of 37.9%. Nationally, 35.7% of adults hold at least a bachelor's degree. The high school graduation rate (or equivalent) is 83.5%.

Data Sources & Methodology

All demographic data for Lenzburg, Illinois is sourced from the U.S. Census Bureau's American Community Survey (ACS) 2020–2024 5-Year Estimates. The ACS collects data from approximately 3.5 million households annually and pools five years of responses so that even small communities can be measured, though the margin of error widens as the population falls. Comparisons are made against Illinois state averages and national averages calculated from the same dataset. Rankings reflect the city's position among all 1,445 Census-designated places in Illinois. Read more about how these figures are produced on our methodology page, or visit data.census.gov for official data.