Illinois Population 2018

12,768,320

The population of Illinois in 2018 is estimated at 12.77 million. The 2015 Census estimates put the population at 12,859,995, which was a decrease from the 2014 numbers.

Illinois is one of only 7 states that has a negative growth rate in 2016. At -0.17% per year, it is ahead of only West Virginia. Between 2000 and 2010, the population of Illinois grew by a mere 3.3%, compared to the national average US population growth of 9.7%.

The 2016 population makes Illinois the fifth largest state in the USA based on population.

Chicago, Largest City in Illinois

Most of the Illinois population is based in the North East of the state. Chicago, home to 2,720,546 people, remains the largest city in Illinois. It dwarfs the state's other cities. The next largest is Aurora, with 200,661 people.

This marks one of Illinois' defining features -- although it has a large urban population, it is spread through a number of smaller cities. Including Chicago, there are twelve cities with more than 75,000 people.

Many of these smaller cities make up a part of the Chicago Metropolitan Area (prosaically also known as Chicagoland), which holds between 8.3 and 9.8 million people, depending on how you classify its boundaries.

Cook County is the largest county in Illinois, housing 5,238,216 people. The next largest county is neighboring Dupage, with 933,736 people. Almost half of the Illinois population can be found in just those two counties.

Illinois Population History

Illinois was included in the Northwest Territory established in 1787 and then in Indiana Territory (1800). Illinois Territory was established in 1809, and included virtually all of present-day Wisconsin and portions of Minnesota and the Upper Peninsula of Michigan. Illinois was admitted as a State on December 3, 1818 with essentially its present boundaries.

In 1790 the Northwest Territory had no census coverage. The population shown for 1800 is the total of two counties and one community in present-day Illinois, at that time part of Indiana Territory. Knox County, Indiana Territory, also included some population in what is now Illinois. In 1810, the returns for the two counties of Illinois Territory included some settlements in present-day Wisconsin. The northern part of the State was not fully covered by the census until 1830.

Illinois Population Chart

Illinois Population History

Illinois saw massive growth throughout the 19th century, from a measley 2,458 people in 1800 to nearly 5 million in 1900. This rise made Illinois the 3rd largest state by the turn of the century. Growth continued into the 20th century, albeit at a slower pace.

Illinois Population Growth

In Illinois' cities, population growth has stalled. Chicago was, for much of its early history, one of America's fastest growing cities. Between 1850 and 1930, the city grew by at least 25% each decade, and in some decades it doubled or even tripled in size. However, from the 1960s onwards, Chicago has been steadily shrinking and a city which was home to 3.5 million people in 1960 is home to just 2.7 million today.

If the current decline continues, Illinois will fall back to the 6th spot in state rankings at the 2020 Census, behind Pennsylvania.

Some estimates expect Illinois to see growth again by 2020, and possibly reach 13.1 million in 2020.

Population Data via US Census

Illinois Growth Rate

Illinois Population Rank

Year Pop % Change
202012,700,914-0.26%
201912,734,617-0.26%
201812,768,320-0.26%
201712,802,023-0.26%
201612,835,726-100.00%
201612,851,684-0.08%
201512,862,051-0.16%
201412,882,438-0.06%
201312,890,4030.09%
201212,878,4940.13%
201112,862,2980.16%
201012,841,1960.33%
200012,419,2930.83%
199011,430,6020.00%
198011,426,5180.28%
197011,113,9760.98%
196010,081,1581.47%
19508,712,1760.99%
19407,897,2410.34%
19307,630,6541.64%
19206,485,2801.41%
19105,638,5911.58%
19004,821,5502.34%
18903,826,3512.20%
18803,077,8711.94%
18702,539,8914.02%
18601,711,9517.23%
1850851,4705.98%
1840476,18311.70%
1830157,44511.05%
182055,21116.22%
181012,28217.45%
18002,4580.00%

Illinois Facts

Illinois Population in 2018Source: By Adrian104 [Public domain], from Wikimedia Commons

  • Illinois has the world's only river that flows backwards.
  • Chicago's Lincoln Park Zoo is the country's oldest public zoo.
  • Almost 80% of the land in Illinois is farm land.
  • The Sears Tower, located in Chicago, is the tallest building in North America.
  • In 1865, Illinois ratified the 13th Amendment to abolish slavery. It was the first state to do so.
  • There are 102 counties in the state of Illinois.
  • The world's largest public library is the Chicago Public Library, which houses over 2 million books.
  • Chicago was the home of the first aquarium, which opened in 1893.
  • The oldest community in Illinois is Peoria.

Illinois Population Density by County

Cook County

  • Population5,211,263
  • Density5512.62 per sq km
  • Growth Since 20100.23%
  • State Rank1
  • % of State40.71%

Illinois Population Growth Rate by County

When looking at population growth of the state of Illinois by county, the data show that the majority of counties have seen population declines. However, there were still a handful of counties that saw small rates of growth, based on data taken from the 2010 Census and again during 2015 estimates taken by the US Census Bureau. During this 5-year period, Kendall County exhibited the most growth at a rate of 6.98%. Other counties that saw growth during this time period include Kane County at 2.86%, Champaign at 3.66%, and Monroe at 2.63%.

There were far more counties that experienced declines in population. This includes Alexander County, which by far had the biggest decline percentage at over 17%. Other counties with declining populations include Mason at 6.49%, Livinsgton at 5.66%, and Cass at 5.77%, among others.

Population by Race

Race Population
White9,270,907
Black or African American1,837,612
Some Other Race753,559
Asian655,799
Two or More Races300,222
American Indian and Alaska Native29,399
Native Hawaiian and Other Pacific Islander4,186

Race Data via US Census (2016 ACS 5-Year Survey)

Illinois Population Pyramid 2018

0%2%4%6%8% Male Population0%2%4%6%8% Female Population80757065605550454035302520151050

Data via US Census (2016 ACS 5-Year Survey): Table S0101

Illinois Median Age

37.4


Total

36.1


Male

38.7


Female

Illinois Adults

There are 9,857,242 adults, (1,786,384 of which are seniors) in Illinois.

Illinois Age Dependency

59.1

Age Dependency Ratio

22.1

Old Age Dependency Ratio

37

Child Dependency Ratio

Illinois Sex Ratio

Female

6,541,224

50.90%

Male

6,310,460

49.10%

Illinois Households and Families

Illinois Renter vs Owner Occupied by Household Type

Illinois Household Types

Type Owner Renter
Married82.9%17.1%
All66%34%
Male57.1%42.9%
Non Family50.7%49.3%
Female46.9%53.1%

66.0%

Rate of Home Ownership

Illinois Households by Type

Type Count Average Size Owned
All4,802,1242.6166
Married2,299,5493.382.9
Non Family1,679,5271.2550.7
Female602,6973.4746.9
Male220,3513.4757.1

3.27

Average Family Size

2.61

Average Household Size

5.4%

Unmarried (Opposite Sex)

0.4%

Unmarried (Same Sex)

Illinois Households

Illinois Education

Illinois Educational Attainment by Sex (over 25)

Education Attained Count Percentage
Less Than 9th Grade454,7575.28%
9th to 12th Grade553,8516.43%
High School Graduate2,287,12626.54%
Some College1,815,86021.07%
Associates Degree671,8217.80%
Bachelors Degree1,744,26020.24%
Graduate Degree1,090,60912.65%

Illinois Educational Attainment by Race

Name Total High School Bachelors
White5,764,1845,388,8842,117,983
Hispanic1,161,879745,680157,769
Black1,145,915977,344233,962
Asian454,746412,934288,812
Other Race419,997243,85139,969
Multiple Races112,08099,33540,282
Native American19,35815,0233,509
Islander2,7312,319713

The highest rate of high school graduation is among white people with a rate of 93.49%.

The highest rate of bachelors degrees is among white people with a rate of 63.51%.

Illinois Earnings by Educational Attainment

Name Average Male Female
Overall$39,672$46,707$32,007
Less Than High School$21,827$25,853$17,085
High School Grad$29,619$35,699$22,757
Some College$35,496$43,898$28,859
Bachelors Degree$52,862$65,828$43,652
Graduate Degree$70,220$87,583$59,501

$39,672

Average Earnings

$46,707

Average Male

$32,007

Average Female

Illinois Language

Illinois Language by Age

Illinois Language

77.34% of Illinois residents speak only English, while 22.66% speak other languages. The largest non-English language is Spanish, which is spoken by 13.23% of the population.

Illinois Poverty

Illinois Poverty by Race

Name Total In Poverty Poverty Rate
White7,827,787705,8969.02%
Black1,758,582522,57729.72%
Hispanic2,101,481411,74919.59%
Other745,769158,06621.20%
Asian642,36275,73311.79%
Multiple291,58053,58718.38%
Native28,7526,06721.10%
Islander4,01250612.61%

13.98%

Overall Poverty Rate

12.69%

Male Poverty Rate

15.20%

Female Poverty Rate

Poverty in Illinois

The race most likely to be in poverty in Illinois is Black, with 29.72% below the poverty level.

The race least likely to be in poverty in Illinois is White, with 9.02% below the poverty level.

The poverty rate among those that worked full-time for the past 12 months was 2.51%. Among those working part-time, it was 16.53%, and for those that did not work, the poverty rate was 22.47%.

Illinois Poverty Rate by Education

Name Poverty
Less Than High School24.45%
High School13.74%
Some College10.20%
Bachelors or Greater4.48%

Illinois Poverty Rate by Employment Status and Sex

Name Poverty
Female Unemployed36.64%
Male Unemployed29.38%
Female Employed7.61%
Male Employed5.32%

Illinois Income

Illinois Income by Household Type

Name Median Mean
Households$59,196$81,865
Families$73,714$97,197
Married Families$88,666$113,775
Non Families$35,106$50,656

Illinois Marital Status

Illinois Marital Status

Marriage Rates

47.8%

Overall Marriage Rate

49.6%

Male Marriage Rate

46.0%

Female Marriage Rate

Illinois Married by Age and Sex

Illinois Marriage

The age group where males are most likely to be married is Over65, while the female age group most likely to be married is 45To54.

Illinois Marital Status by Race

Illinois Veterans

Illinois Veterans by War

643,460

Number of Veterans

601,286

Male Veterans

42,174

Female Veterans

Name Veterans
Vietnam230,748
First Gulf War100,366
Second Gulf War78,716
Korea70,647
World War II43,462

Illinois Veterans by Age

Name Veterans
65 to 74168,205
75+163,222
35 to 54141,919
55 to 64118,066
18 to 3452,048

Illinois Veterans by Race

Name Veterans % of Total
White534,8157.35%
Black84,6246.21%
Hispanic27,6591.96%
2 or More8,5315.72%
Other7,4951.47%
Asian6,0611.17%
Indian1,6627.47%
Hawaiian2728.27%

Illinois Veterans by Education

7.05%

Veteran Poverty Rate

27.01%

Veteran Disability Rate

Illinois Employment Status

Illinois Employment by Age

65.6%

Labor Force Participation

60.1%

Employment Rate

8.2%

Unemployment Rate

Illinois Employment by Race

Illinois Employment by Education

Illinois Nativity

Illinois Citizenship Status

Data Sources
  1. US Census State Population Estimates - Most recent state estimates from the Census Bureau's Population Estimates Program
  2. US Census County Population Estimates - Most recent county estimates from the Census Bureau's Population Estimates Program
  3. American Community Survey (2009 - 2013)
  4. Census QuickFacts
  5. Historical Populations of States and Counties (1790 - 1990)