Population density in Illinois

Population density in Illinois was 88.5 inhabitants per km² in 2025, according to the U.S. Census Bureau. That is up 0.1% from 2024. That is the 14th highest of 51 states in 2025.

2025, inhabitants per km²88.5
Change on 2024+0.1%
Rank14th of 51US states ranked
Series high892020
Series low87.72022

Population density in Illinois, 2020 to 2025

CSVChart (SVG)

87.58888.5892020202120222023202420252020: 89 inhabitants per km²2021: 88.4 inhabitants per km²2022: 87.7 inhabitants per km²2023: 87.9 inhabitants per km²2024: 88.4 inhabitants per km²2025: 88.5 inhabitants per km²
inhabitants per km². Source: Invokely calculation with data from U.S. Census Bureau. Retrieved 2026-10-09, published 2026-03-26.
All 6 values
Periodinhabitants per km²
202588.5
202488.4
202387.9
202287.7
202188.4
202089

Compared with United States

Place2025
Illinois88.5
United States37.3

Rankings

Definition

Resident population divided by land area in km². World Bank figures use mid-year population and land area excluding inland water.

United States: Census Bureau population estimates for 1 July divided by land area (water excluded) from the latest Census Gazetteer files. US tables often give people per square mile; multiply persons per km² by 2.59 to compare.

How to cite

U.S. Census Bureau. Population Estimates Program resident population on 1 July divided by land area from the latest Census Gazetteer files, persons per km². https://www2.census.gov/programs-surveys/popest/datasets/2020-2025/. Retrieved 2026-10-09.

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Questions

What is the population density in Illinois?

Population density in Illinois was 88.5 inhabitants per km² in 2025, according to the U.S. Census Bureau. That is up 0.1% from 2024. That is the 14th highest of 51 states in 2025.

Where does this figure come from?

U.S. Census Bureau. Population Estimates Program resident population on 1 July divided by land area from the latest Census Gazetteer files, persons per km². Retrieved by Invokely on 2026-10-09.

What was the highest population density in Illinois?

89 inhabitants per km² in 2020, the highest value since 2020 in this series.

More statistics for Illinois

All statistics for Illinois