Share of the population by age and sex, five-year groups

Population of Illinois, 2010–2025 · click to pick a year
Estimates up to 2019 are built on the 2010 Census, those from 2020 on the 2020 Census. A line that steps up or down between 2019 and 2020 reflects this re-basing, not a sudden change in population.

Year

-5 -1   2018  +1 +5

12,724,685 people lived in Illinois on July 1, 2018: the 6th-largest population among the 50 states and the District of Columbia. The median age was 38.3 years (United States: 38.2); children (18.5%) and older adults (15.6%) make up similar shares of the population. There were 96.6 men for every 100 women. Since 2010 the population has shrunk by 0.9%. Source: U.S. Census Bureau, Population Estimates Program, Vintage 2020 estimates (resident population on July 1; public domain). Median age, shares, dependency ratios and rankings are calculated by PopulationPyramid.net from these estimates; the Census Bureau does not endorse this site.

Key indicators, 2018
Population
12,724,685
Rank by population
6th of 51
Median age
38.3
Men per 100 women
96.6
Under 15
18.5%
15–64
65.8%
65 and over
15.6%
Child dependency
28.1
Old-age dependency
23.7
Change since 2010
-0.9%
Dependency ratios count children under 15 or adults 65 and over per 100 residents aged 15 to 64.
Show the population by age group, 2018
AgeMenWomenTotalShare
0-4388,358371,390759,7486.0%
5-9397,492380,465777,9576.1%
10-14417,995402,053820,0486.4%
15-19423,226405,158828,3846.5%
20-24429,402415,494844,8966.6%
25-29457,016445,431902,4477.1%
30-34437,145428,166865,3116.8%
35-39426,986426,589853,5756.7%
40-44391,068392,142783,2106.2%
45-49404,088412,101816,1896.4%
50-54404,489415,869820,3586.4%
55-59422,790443,789866,5796.8%
60-64383,026413,648796,6746.3%
65-69305,328343,373648,7015.1%
70-74225,684266,233491,9173.9%
75-79151,477196,163347,6402.7%
80-8496,770138,556235,3261.8%
85+89,755175,970265,7252.1%
How Illinois compares with similar-sized states, 2018
RankStateResidentsRelative
3 Florida 21,254,926
4 New York 19,544,098
5 Pennsylvania 12,809,107
6 Illinois 12,724,685
7 Ohio 11,680,892
8 Georgia 10,519,389
9 North Carolina 10,391,358
Frequently asked questions about Illinois's population
What is the population of Illinois?
Illinois had an estimated 12,724,685 residents on July 1, 2018, according to the U.S. Census Bureau, Population Estimates Program. That ranks 6th among the 51 states and the District of Columbia.
What is the median age in Illinois?
The median age in Illinois was 38.3 years in 2018, the 27th oldest of the 51 states and DC. That is 0.1 years older than the national median of 38.2.
How many people in Illinois are 65 or older?
About 1,989,309 residents of Illinois (15.6%) were 65 or older in 2018, against 18.5% under 15 and 65.8% aged 15 to 64.
What does the population pyramid of Illinois show?
In 2018, Illinois: children (18.5%) and older adults (15.6%) make up similar shares of the population. There were 96.6 men for every 100 women.
How fast is the population of Illinois changing?
The population of Illinois shrank by 0.9% between 2010 and 2018, and by -0.4% in the last year.
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