Waterloo, IL Profile: Facts & Data

Waterloo, Illinois - Basic Facts

The City of Waterloo had a population of 11,033 as of July 1, 2025.

The primary coordinate point for Waterloo is located at latitude 38.3359 and longitude -90.1498 in Monroe County. The formal boundaries for the City of Waterloo encompass a land area of 8.13 sq. miles and a water area of 0.14 sq. miles. Monroe County is in the Central time zone (GMT -6).

The City of Waterloo has a C1 Census Class Code which indicates an active incorporated place that does not serve as a county subdivision equivalent. It also has a Functional Status Code of "A" which identifies an active government providing primary general-purpose functions.

The City of Waterloo is located within Precinct 31 Election Precinct, a minor civil division (MCD) of Monroe County.

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Waterloo, IL Data & Demographics (As of July 1, 2025)

POPULATION
Total Population	11,033 (100%)
Population in Households	10,824 (98.1%)
Population in Families	8,847 (80.2%)
Population in Group Quarters¹	209 ( 1.9%)
Population Density	1,332
Diversity Index²	17


INCOME
Median Household Income	$95,607
Average Household Income	$112,091
% of Income for Mortgage⁴	17%
Per Capita Income	$47,327
Wealth Index⁵	100
Socioeconomic Status Index⁶	Moderate (58.8)

HOUSING
Total HU (Housing Units)	4,856 (100%)
Owner Occupied HU	3,639 (74.9%)
Renter Occupied HU	1,013 (20.9%)
Vacant Housing Units	204 ( 4.2%)
Median Home Value	$262,595
Average Home Value	$302,215
Housing Affordability Index³	123

HOUSEHOLDS
Total Households	4,652
Average Household Size	2.33
Family Households	3,130
Average Family Size	3.00

HOUSING

Total HU (Housing Units)

4,856 (100%)

Owner Occupied HU

3,639 (74.9%)

Renter Occupied HU

1,013 (20.9%)

Vacant Housing Units

204 ( 4.2%)

Median Home Value

$262,595

Average Home Value

$302,215

Housing Affordability Index³

123

HOUSEHOLDS

Total Households

4,652

Average Household Size

2.33

Family Households

3,130

Average Family Size

3.00

NOTES

Group Quarters - a place where people live or stay in a group living arrangement. Includes college residents halls, nursing facilities, military barracks, and correctional facilities.
The Diversity Index is a scale of 0 to 100 that represents the likelihood that two persons, chosen at random from the same area, belong to different races or ethnic groups. If an area's entire population belongs to one race AND one ethnic group, then the area has zero diversity. An area's diversity index increases to 100 when the population is evenly divided into two or more race/ethnic groups.
The Housing Affordability Index base is 100 and represents a balance point where a resident with a median household income can normally qualify to purchase a median price home. Values above 100 indicate increased affordability, while values below 100 indicate decreased affordability.
The % of Income for Mortgage quantifies the percentage of median household income dedicated to mortgage payments on a home priced at the median value (assuming a 30-year mortgage and a 20% down payment).
The Wealth Index is based on a number of indicators of affluence including average household income and average net worth, but it also includes the value of material possessions and resources. It represents the wealth of the area relative to the national level. Values above or below 100 represent above-average wealth or below-average wealth compared to the national level.
The Socioeconomic Index ranges from zero (lowest relative status) to 100 (highest relative status). This measure quantifies disparities in social position of an area's inhabitants and is built from a broad range of demographic, housing, and socioeconomic inputs. More information on this measure can be found in Esri's SEI tutorial.

GROWTH RATE / YEAR	2020-2025	2025-2030
Population	0.03%	0.05%
Households	0.78%	0.49%
Families		0.27%
Median Household Income		1.88%
Per Capita Income		2.01%
Owner Occupied HU		0.86%

GROWTH RATE / YEAR

2020-2025

2025-2030

Population

0.03%

0.05%

Households

0.78%

0.49%

Families

0.27%

Median Household Income

1.88%

Per Capita Income

2.01%

Owner Occupied HU

0.86%

Waterloo, IL - Peer Comparisons by Rank and Percentile

The table below compares Waterloo to the other 1,461 incorporated cities, towns and CDPs in Illinois by rank and percentile using July 1, 2025 data. The location Ranked # 1 has the highest value. A location that ranks higher than 75% of its peers would be in the 75th percentile of the peer group.

Variable Description	Rank	Percentile
Total Population	# 206	86th
Population Density	# 490	67th
Median Household Income	# 365	75th
Housing Affordability Index	# 694	48th
Per Capita Income	# 385	74th
Diversity Index	# 943	36th

Variable Description

Rank

Percentile

Total Population

# 206

86th

Population Density

# 490

67th

Median Household Income

# 365

75th

Housing Affordability Index

# 694

48th

Per Capita Income

# 385

74th

Diversity Index

# 943

36th

Illinois Census Data Comparison Tool

Waterloo, IL Profile: Facts & Data

Waterloo, Illinois - Basic Facts

Waterloo, IL Data & Demographics (As of July 1, 2025)

POPULATION

INCOME

HOUSING

HOUSEHOLDS

GROWTH RATE / YEAR

Waterloo, IL - Peer Comparisons by Rank and Percentile

Waterloo, IL - Most Popular Things to Do

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Monroe County