Assumption, IL

City in Christian County, IL, US

By Neilsberg Research

Last updated May 1, 2026

Key Indicators

A quick look at key numbers

Population

1,205

Source: U.S. Census Bureau American Community Survey (ACS) 2020-2024 5-Year Estimates

Median Age

37.2

years ∙ half population younger than 37.2, half older

Diversity Index

21.5%

chance two random people differ in race and ethnicity

Nativity

0.2%

foreign-born population

99.8%Native

0.2% Foreign-born

Geographic Context

Location, size, and surroundings

About

Assumption is a city within Christian County, Illinois, United States.

Location

City in Christian County, IL, US

Co-ordinates

DEC39.518002° N, 89.047729° W

DMS39° 31′ 04.81″ N, 89° 02′ 51.82″ W

Population Density & area

1,217/sq mi (470/km²)

Total Area

0.99 sq mi (2.564 km²)

Land Area

0.99 sq mi (2.564 km²) · 100%

Water Area

0 sq mi (0 km²) · 0%

Demographics & Living

Who lives here, how households are formed, and community composition

Population Composition

Key characteristics of the population

Sex Distribution

54.5% male

Male 54.5%

Female 45.5%

males per 100 females

Assumption 119.9

Christian County 112.2

Illinois 97.7

Nativity

0.2%

foreign-born population

99.8%Native

0.2% Foreign-born

% Foreign-born

Assumption 0.2%

Christian County 1.2%

Illinois 14.7%

Age Distribution

How the population is spread across age groups

Median Age

37.2

years ∙ half population younger than 37.2, half older

Assumption

37.2

Christian County

43.2

Illinois

Dependency ratio

dependents per 100 working-age adults

Assumption 48

Christian County 65.5

Illinois 63.5

AGE DISTRIBUTION

Distribution of age group

Median age

	Assumption	Christian County	Illinois
Age Group
Children (Under 18)	18%	19.3%	21.8%
Working age (18-64)	67.6%	60.4%	61.2%
Senior (65+)	14.4%	20.3%	17%
Dependency ratio
Total dependency ratio	48	65.5	63.5
Child dependency ratio	26.7	32	35.7
Old-age dependency ratio	21.4	33.6	27.8

Racial & Ethnic Composition

Racial and ethnic makeup and how it compares

Race & Ethnicity

White

88.3%

Black

3.3%

Asian

Hispanic

2.3%

Other

6.1%

Note: White, Black, and Asian refer to individuals belonging to a single race and not of Hispanic origin. Hispanics may be of any race.

Diversity Index

21.5%

chance two random people differ in race and ethnicity

Assumption 21.5%

Christian County 17%

Illinois 60.5%

Note: The Diversity Index (DI), based on the Blau Index, measures the probability that two randomly selected individuals differ in race and ethnicity. Values range from 0 (no diversity) to 1 (high diversity) and are shown as percentages.

RACIAL & ETHNIC COMPOSITION

Race & Ethnicity

Percentage of Assumption population

	Assumption	Christian County	Illinois
Hispanic or Latino	2.3%	3.3%	18.8%
Mexican	2.3%	1.8%	14.4%
Puerto Rican	0%	0.2%	1.6%
Cuban	0%	0.3%	0.3%
Other Hispanic / Latino	0%	1.1%	2.5%
Not Hispanic or Latino	97.7%	96.7%	81.2%
One race	92%	94.3%	77.8%
White	88.3%	91%	58.1%
Black or African American	3.3%	2.1%	13.3%
American Indian and Alaska Native	0.1%	0%	0.1%
Asian	0%	0.7%	5.9%
Native Hawaiian and Other Pacific Islander	0.2%	0%	0%
Some Other Race	0%	0.3%	0.4%
Two or more races (Multiracial)	5.7%	2.4%	3.4%

Household & Families Composition

Household size, type, and family structure

Household structure

49.5% family

Family 49.5%

Non family 50.5%

% family households

Assumption 49.5%

Christian County 57.6%

Illinois 62.2%

Average household size

2.01

persons per household

Assumption

2.01

Christian County

2.34

Illinois

2.46

Household & Family COMPOSITION

Households

Percentage of Assumption population

	Assumption	Christian County	Illinois
Total households	600	13,586	5,036,449
Average houshold size	2.01	2.34	2.46
Family households	297	7,829	3,130,978
Average family size	2.73	3.13	3.14
Married couple family	172	6,097	2,282,435
Other families	125	1,732	848,543
Male householder	44	489	248,521
Female householder	81	1,243	600,022
Non-family households	303	5,757	1,905,471
One-person households	232	4,965	1,569,881
Male householder	169	2,428	712,191
Senior (65+) living alone	20	955	210,051
Female householder	63	2,537	857,690
Senior (65+) living alone	45	1,452	417,870
Other living arrangements	71	792	335,590

Housing Profile

Housing stock, ownership, rentals, and cost burdens

Total housing units

672

housing units

Assumption 672

Christian County 15,184

Illinois 5,457,452

Occupancy status

89.3% occupied

Occupied 89.3%

Vacant 10.7%

vacancy rate

Assumption 10.7%

Christian County 10.5%

Illinois 7.7%

Housing Characteristics

How the housing supply is structured and used

Types of Housing unit

89.1%

Single family houses

89.1%

Apartments in multi-unit structures

8.6%

Mobile homes

2.2%

Boat, RV, van, etc

Median Year Built

1952

Half of houses were built before 1952, and half after.

Historic ∙ 1939 or earlier

36.2%

Postwar & mid-century ∙ 1940 - 1969

41.1%

Late 20th century ∙ 1970 - 1999

18.6%

Modern ∙ 2000 or later

3.9%

Note: Median year built reflects occupied units only; distribution includes all units.

Housing Characteristics

Units, rooms & bedrooms

Physical characteristics of housing units

	Assumption	Christian County	Illinois
Rooms per unit
Median rooms	5.4	5.5	5.6
1–3 rooms	15.6%	8.2%	14.6%
4–6 rooms	50.7%	60.7%	50.9%
7+ rooms	33.6%	31.1%	34.6%
Bedrooms
No bedroom / studio	0%	0.5%	3.1%
1 bedroom	10%	9.1%	11.5%
2 bedrooms	32.4%	33.1%	27.7%
3 bedrooms	47.3%	44.4%	35.8%
4+ bedrooms	10.3%	12.9%	21.7%
At a glance
Median year built	1952	1963	1971
Total housing units	672	15,184	5,457,452

Occupancy Profile

Who is inside and how they use it

Homeownership

64.2% owners

Renter-occupied 35.8%

Owner-occupied 64.2%

homeownership rate

Assumption 64.2%

Christian County 75.2%

Illinois 67.1%

Average household size

2.22

Owner-occupied

1.63

Renter-occupied

owner-occupied average size

Assumption 2.22

Christian County 2.41

Illinois 2.62

Housing Characteristics

Occupied unit characteristics

Tenure, crowding, and utilities

	Assumption	Christian County	Illinois
Total occupied units	600	13,586	5,036,449
Year moved in
2020 or later	14%	17.8%	23.3%
2010 to 2019	47.7%	37.5%	38.1%
2000 to 2009	13.8%	18.7%	17.3%
1999 or earlier	24.5%	25.9%	21.3%
Occupants per room
1.00 or fewer	100%	99.2%	97.5%
1.01 to 1.50	0%	0.6%	1.6%
1.51 or more	0%	0.2%	0.8%
Vehicles availability
No vehicles	4.8%	6.1%	11%
1 vehicle	38%	32.5%	35.7%
2 vehicles	39.5%	37.9%	35.1%
3 or more vehicles	17.7%	23.6%	18.3%
House heating fuel used
Gas	79.7%	79.7%	79.5%
Electricity	19%	18.8%	18.6%
Solar	0%	0.1%	0.1%
Fuel oil, kerosene etc	0%	0%	0.1%
All other fuels	0%	1.1%	0.8%
No fuel used	1.3%	0.2%	0.8%
Selected characteristics
Lacking complete plumbing	0%	0.1%	0.3%
Lacking complete kitchen	0%	0.7%	0.8%
No telephone service available	0.8%	0.5%	0.8%

Housing Value

What owner-occupied units are worth

Median home value

$89,700

owner-occupied units

Median value(USD)

Assumption

$89,700

Christian County

$115,500

Illinois

$263,300

Housing Cost Burden

18.9%

of homeowners with a mortgage are cost-burdened

% Cost-Burdened Households

Owners with a mortgage

18.9%

Owners without a mortgage

1.2%

Renters

22.1%

Note: Households spending 30% or more of their income on housing costs are considered cost-burdened.

Financial characteristics

Property value and housing costs

Tenure, crowding, and utilities

	Assumption	Christian County	Illinois
Property value
Median Value	$89,700	$115,500	$263,300
Under $100,000	61.8%	42.4%	13.7%
$100,000 - $200,000	30.2%	32.5%	21.5%
$200,000 - $300,000	6.8%	15.5%	22.3%
$300,000 - $500,000	0.8%	8.1%	27.7%
$500,000 - $1,000,000	0.5%	1.2%	12.1%
$1,000,000 and more	0%	0.3%	2.7%
Owner-occupied households
With a mortgage	57.9%	52.4%	60.8%
Without a mortgage	42.1%	47.6%	39.2%
Median monthly owner costs
With a mortgage	$850	$1,200	$1,987
Without a mortgage	$580	$535	$792
Gross rent
Median rent	$693	$785	$1,274

Education Profile

How educated is the community and how education pays off

Adults with a college degree

16.6%

of adults 25+ with a bachelor's degree or higher

Assumption 16.6%

Christian County 17.1%

Illinois 37.8%

Adults without a high school diploma

4.7%

of adults (25+) without a high school diploma

Assumption 4.7%

Christian County 9.1%

Illinois 9.6%

School Enrollment

Who is enrolled in school and at what level

School enrollment

223

population (age 3+) enrolled in school

Nursery / Preschool

14.3%

K–12

63.2%

College / Undergraduate

22%

Graduate / Professional

0.4%

College-going rate (18-24 yr olds)

17%

of 18-24-year-olds in college or graduate school

Assumption

17%

Christian County

28.9%

Illinois

41.4%

Enrollment & school type

Enrollment levels, college-going rate, and public vs private school split

Population 3+ currently enrolled in a school

	Assumption	Christian County	Illinois
Total enrolled (age 3+)	223	6,664	3,051,569
Nursery / preschool	14.3%	9.8%	6.3%
K–12	63.2%	72.5%	67.3%
Kindergarten	4.9%	4.5%	4.9%
Elementary: Grades 1–4	16.1%	24.1%	19.5%
Elementary: Grades 5–8	10.3%	19.5%	20.8%
High School: Grades 9–12	31.8%	24.4%	22.1%
College or graduate school	22.4%	17.8%	26.4%
College, undergraduate	22%	14.8%	19.8%
Graduate, professional school	0.4%	3%	6.6%
College-going rate · 18-24 yr olds	17%	28.9%	41.4%
School type
Public school	89.2%	87.4%	80.5%
Private school	10.8%	12.6%	19.5%

Education Attainment by Level & Gender

What is the highest level of education completed among adults

Education attainment

758

population 25 years and over

Total adults (25+)

Less than 9th grade

2.1%

9th-12th, no diploma

2.6%

HS graduate

51.3%

Some college no degree

23.5%

Associates degree

3.8%

Bachelors degree

11.1%

Graduate or professional degree

5.5%

Attainment by gender

Male vs Female

Adults (25+) · Share within each education level

% male · % female

Less than 9th grade

100% · 0%

9th-12th, no diploma

95% · 5%

HS graduate

57.8% · 42.2%

Some college no degree

61.8% · 38.2%

Associates degree

62.1% · 37.9%

Bachelors degree

53.6% · 46.4%

Graduate or professional degree

7.1% · 92.9%

Educational Attainment Overview

Distribution and key education attainment rates for adults (25+)

Highest credential completed · adults 25+

	Assumption	Christian County	Illinois
Population (25+)	758	24,493	8,767,004
Less than 9th grade	2.1%	2.5%	4.6%
9th–12th, no diploma	2.6%	6.6%	5%
High school diploma or GED	51.3%	45%	25.1%
Some college, no degree	23.5%	18.9%	19.2%
Associate's degree	3.8%	9.8%	8.3%
Bachelor's degree or higher	16.6%	17.1%	37.8%
Bachelor's degree	11.1%	12.1%	22.6%
Graduate or professional	5.5%	5%	15.3%
High School or higher	95.3%	90.9%	90.5%

Earnings by education level

percentage as applicable

Median Earnings

$60,320

Median earnings for adults 25+, by level

Less than HS graduate

$91,250

HS graduate

$42,903

Some college or associates

$65,625

Bachelors degree

$70,333

Graduate or professional degree

$62,188

Poverty Rate

for ages 25+, with bachelors degree or higher

Less than HS graduate

8.3%

HS graduate

14.9%

Some college or associates

6.8%

Bachelors degree or higher

Outcomes by Education Level

Earnings and poverty rates across education levels (25+)

Adults 25+

	Assumption	Christian County	Illinois
Median earnings
Population 25+, with earnings	$60,320	$47,025	$55,582
Less than high school graduate	$91,250	$31,188	$34,655
High school graduate (includes equivalency)	$42,903	$42,716	$40,965
Some college or associate's degree	$65,625	$47,345	$47,813
Bachelor's degree	$70,333	$52,884	$73,326
Graduate or professional degree	$62,188	$75,714	$91,623
Poverty rates
Less than high school graduate	8.3%	23.1%	21.6%
High school graduate (includes equivalency)	14.9%	11.7%	14.4%
Some college or associate's degree	6.8%	8.2%	9.9%
Bachelor's degree or higher	0%	3.8%	4.5%

Insights for Assumption, by topic

Income By year By race By age By gender

Population By year By race By age By gender

About Neilsberg Research

Neilsberg Research team are data scientists with expertise in processing, analysis and visualization of big data helping small businesses make right decisions.

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