Grundy County, Iowa

County in IA, US

By Neilsberg Research

Last updated May 1, 2026

Key Indicators

A quick look at key numbers

Population

12,384

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

Median Age

41.9

years ∙ half population younger than 41.9, half older

Diversity Index

9.9%

chance two random people differ in race and ethnicity

Nativity

1.7%

foreign-born population

98.3%Native

1.7% Foreign-born

Geographic Context

Location, size, and surroundings

About

Grundy County is a county in Iowa, United States.

Location

County in IA, US

Co-ordinates

DEC42.403339° N, 92.790244° W

DMS42° 24′ 12.02″ N, 92° 47′ 24.88″ W

Population Density & area

24.67/sq mi (9.53/km²)

Total Area

501.9 sq mi (1,299.9 km²)

Land Area

501.9 sq mi (1,299.8 km²) · 99.99%

Water Area

0 sq mi (0.1 km²) · 0.01%

Demographics & Living

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

Population Composition

Key characteristics of the population

Sex Distribution

49.5% male

Male 49.5%

Female 50.5%

males per 100 females

Grundy County 98

Iowa 100.6

United States 98

Nativity

1.7%

foreign-born population

98.3%Native

1.7% Foreign-born

% Foreign-born

Grundy County 1.7%

Iowa 5.9%

United States 14.1%

Age Distribution

How the population is spread across age groups

Median Age

41.9

years ∙ half population younger than 41.9, half older

Grundy County

41.9

Iowa

38.6

United States

38.9

Dependency ratio

dependents per 100 working-age adults

Grundy County 80

Iowa 69.6

United States 64.4

AGE DISTRIBUTION

Distribution of age group

Median age

	Grundy County	Iowa	United States
Age Group
Children (Under 18)	23.5%	22.9%	22%
Working age (18-64)	55.5%	59%	60.8%
Senior (65+)	21%	18.1%	17.2%
Dependency ratio
Total dependency ratio	80	69.6	64.4
Child dependency ratio	42.2	38.8	36.1
Old-age dependency ratio	37.8	30.7	28.3

Racial & Ethnic Composition

Racial and ethnic makeup and how it compares

Race & Ethnicity

White

94.9%

Black

0.6%

Asian

0.5%

Hispanic

1.8%

Other

2.2%

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

9.9%

chance two random people differ in race and ethnicity

Grundy County 9.9%

Iowa 31.4%

United States 61.4%

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 Grundy County population

	Grundy County	Iowa	United States
Hispanic or Latino	1.8%	7.3%	19.3%
Mexican	1%	5%	11.3%
Puerto Rican	0.2%	0.3%	1.8%
Cuban	0%	0.1%	0.8%
Other Hispanic / Latino	0.6%	1.8%	5.5%
Not Hispanic or Latino	98.2%	92.7%	80.7%
One race	97.1%	89.2%	76.4%
White	94.9%	82.3%	57.4%
Black or African American	0.6%	3.8%	11.9%
American Indian and Alaska Native	0.5%	0.2%	0.5%
Asian	0.5%	2.5%	5.9%
Native Hawaiian and Other Pacific Islander	0%	0.2%	0.2%
Some Other Race	0.8%	0.3%	0.6%
Two or more races (Multiracial)	1.1%	3.5%	4.3%

Household & Families Composition

Household size, type, and family structure

Household structure

67.9% family

Family 67.9%

Non family 32.1%

% family households

Grundy County 67.9%

Iowa 61.6%

United States 64.2%

Average household size

2.39

persons per household

Grundy County

2.39

Iowa

2.36

United States

2.53

Household & Family COMPOSITION

Households

Percentage of Grundy County population

	Grundy County	Iowa	United States
Total households	5,117	1,315,707	129,227,496
Average houshold size	2.39	2.36	2.53
Family households	3,475	809,836	82,990,528
Average family size	2.92	2.98	3.14
Married couple family	2,956	635,347	60,637,388
Other families	519	174,489	22,353,140
Male householder	231	56,457	6,572,819
Female householder	288	118,032	15,780,321
Non-family households	1,642	505,871	46,236,968
One-person households	1,473	406,436	37,140,836
Male householder	657	193,582	16,871,444
Senior (65+) living alone	268	58,028	5,225,110
Female householder	816	212,854	20,269,392
Senior (65+) living alone	551	111,645	10,089,070
Other living arrangements	169	99,435	9,096,132

Housing Profile

Housing stock, ownership, rentals, and cost burdens

Total housing units

5,498

housing units

Grundy County 5,498

Iowa 1,437,699

United States 143,775,355

Occupancy status

93.1% occupied

Occupied 93.1%

Vacant 6.9%

vacancy rate

Grundy County 6.9%

Iowa 8.5%

United States 10.1%

Housing Characteristics

How the housing supply is structured and used

Types of Housing unit

86.4%

Single family houses

86.4%

Apartments in multi-unit structures

10.8%

Mobile homes

2.9%

Boat, RV, van, etc

Median Year Built

1962

Half of houses were built before 1962, and half after.

Historic ∙ 1939 or earlier

33.4%

Postwar & mid-century ∙ 1940 - 1969

22.8%

Late 20th century ∙ 1970 - 1999

30.4%

Modern ∙ 2000 or later

13.2%

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

Housing Characteristics

Units, rooms & bedrooms

Physical characteristics of housing units

	Grundy County	Iowa	United States
Rooms per unit
Median rooms	6.5	5.9	5.5
1–3 rooms	8.3%	11.8%	15.1%
4–6 rooms	41.8%	47.4%	51.6%
7+ rooms	49.9%	40.7%	33.4%
Bedrooms
No bedroom / studio	0.4%	1.7%	2.9%
1 bedroom	8.4%	9.2%	10.9%
2 bedrooms	19.7%	27%	25%
3 bedrooms	38.4%	37.3%	38.7%
4+ bedrooms	33%	24.7%	22.4%
At a glance
Median year built	1962	1972	1981
Total housing units	5,498	1,437,699	143,775,355

Occupancy Profile

Who is inside and how they use it

Homeownership

84.5% owners

Renter-occupied 15.5%

Owner-occupied 84.5%

homeownership rate

Grundy County 84.5%

Iowa 71.7%

United States 65.2%

Average household size

2.53

Owner-occupied

1.61

Renter-occupied

owner-occupied average size

Grundy County 2.53

Iowa 2.5

United States 2.64

Housing Characteristics

Occupied unit characteristics

Tenure, crowding, and utilities

	Grundy County	Iowa	United States
Total occupied units	5,117	1,315,707	129,227,496
Year moved in
2020 or later	16.3%	24.3%	24.8%
2010 to 2019	37.1%	38.7%	39.6%
2000 to 2009	18.8%	16.4%	16.4%
1999 or earlier	27.9%	20.7%	19.1%
Occupants per room
1.00 or fewer	99.5%	98.4%	96.6%
1.01 to 1.50	0.3%	1.1%	2.2%
1.51 or more	0.2%	0.5%	1.2%
Vehicles availability
No vehicles	3.2%	5.4%	8.4%
1 vehicle	25.6%	30.5%	33.1%
2 vehicles	38.2%	37.8%	36.6%
3 or more vehicles	33%	26.3%	21.9%
House heating fuel used
Gas	80.2%	72.8%	51.4%
Electricity	17.1%	24.4%	41.3%
Solar	0%	0.1%	0.3%
Fuel oil, kerosene etc	0.8%	0.3%	3.9%
All other fuels	1.6%	1.8%	2%
No fuel used	0.4%	0.6%	1.2%
Selected characteristics
Lacking complete plumbing	0.1%	0.3%	0.4%
Lacking complete kitchen	0.7%	0.8%	0.8%
No telephone service available	0.5%	0.8%	0.9%

Housing Value

What owner-occupied units are worth

Median home value

$198,800

owner-occupied units

Median value(USD)

Grundy County

$198,800

Iowa

$208,000

United States

$332,700

Housing Cost Burden

19.8%

of homeowners with a mortgage are cost-burdened

% Cost-Burdened Households

Owners with a mortgage

19.8%

Owners without a mortgage

10.2%

Renters

27.4%

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

	Grundy County	Iowa	United States
Property value
Median Value	$198,800	$208,000	$332,700
Under $100,000	14.6%	17.8%	11.4%
$100,000 - $200,000	35.9%	30%	15.8%
$200,000 - $300,000	27.8%	23.1%	17.8%
$300,000 - $500,000	17.9%	21.3%	26.9%
$500,000 - $1,000,000	3.2%	6.8%	20.9%
$1,000,000 and more	0.7%	1.1%	7.1%
Owner-occupied households
With a mortgage	58.4%	59.4%	60.6%
Without a mortgage	41.6%	40.6%	39.4%
Median monthly owner costs
With a mortgage	$1,489	$1,533	$1,963
Without a mortgage	$608	$616	$638
Gross rent
Median rent	$774	$972	$1,413

Education Profile

How educated is the community and how education pays off

Adults with a college degree

27.8%

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

Grundy County 27.8%

Iowa 31.4%

United States 35.7%

Adults without a high school diploma

3.1%

of adults (25+) without a high school diploma

Grundy County 3.1%

Iowa 6.7%

United States 10.4%

School Enrollment

Who is enrolled in school and at what level

School enrollment

2,998

population (age 3+) enrolled in school

Nursery / Preschool

10.5%

K–12

72.7%

College / Undergraduate

13.9%

Graduate / Professional

2.9%

College-going rate (18-24 yr olds)

33.7%

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

Grundy County

33.7%

Iowa

42.3%

United States

40.9%

Enrollment & school type

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

Population 3+ currently enrolled in a school

	Grundy County	Iowa	United States
Total enrolled (age 3+)	2,998	784,322	80,089,790
Nursery / preschool	10.5%	6.2%	5.7%
K–12	72.7%	68.4%	67.6%
Kindergarten	4.2%	5.2%	5%
Elementary: Grades 1–4	24.2%	20.3%	19.8%
Elementary: Grades 5–8	24%	21.3%	21%
High School: Grades 9–12	20.3%	21.6%	21.7%
College or graduate school	16.8%	25.4%	26.7%
College, undergraduate	13.9%	20.8%	21%
Graduate, professional school	2.9%	4.6%	5.8%
College-going rate · 18-24 yr olds	33.7%	42.3%	40.9%
School type
Public school	92.1%	84.4%	82%
Private school	7.9%	15.6%	18%

Education Attainment by Level & Gender

What is the highest level of education completed among adults

Education attainment

8,643

population 25 years and over

Total adults (25+)

Less than 9th grade

0.6%

9th-12th, no diploma

2.5%

HS graduate

33.3%

Some college no degree

19.6%

Associates degree

16.2%

Bachelors degree

20.4%

Graduate or professional degree

7.4%

Attainment by gender

Male vs Female

Adults (25+) · Share within each education level

% male · % female

Less than 9th grade

71.4% · 28.6%

9th-12th, no diploma

58.3% · 41.7%

HS graduate

59.4% · 40.6%

Some college no degree

44.4% · 55.6%

Associates degree

47.9% · 52.1%

Bachelors degree

43.8% · 56.2%

Graduate or professional degree

35.9% · 64.1%

Educational Attainment Overview

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

Highest credential completed · adults 25+

	Grundy County	Iowa	United States
Population (25+)	8,643	2,154,149	230,807,303
Less than 9th grade	0.6%	2.7%	4.7%
9th–12th, no diploma	2.5%	4%	5.7%
High school diploma or GED	33.3%	30%	26%
Some college, no degree	19.6%	19.7%	19.1%
Associate's degree	16.2%	12.1%	8.8%
Bachelor's degree or higher	27.8%	31.4%	35.7%
Bachelor's degree	20.4%	20.9%	21.6%
Graduate or professional	7.4%	10.5%	14.1%
High School or higher	96.9%	93.3%	89.6%

Earnings by education level

percentage as applicable

Median Earnings

$51,929

Median earnings for adults 25+, by level

Less than HS graduate

$37,000

HS graduate

$45,952

Some college or associates

$47,694

Bachelors degree

$59,375

Graduate or professional degree

$84,044

Poverty Rate

2.7%

for ages 25+, with bachelors degree or higher

Less than HS graduate

30.3%

HS graduate

6.6%

Some college or associates

7.5%

Bachelors degree or higher

2.7%

Outcomes by Education Level

Earnings and poverty rates across education levels (25+)

Adults 25+

	Grundy County	Iowa	United States
Median earnings
Population 25+, with earnings	$51,929	$51,106	$52,696
Less than high school graduate	$37,000	$35,996	$32,485
High school graduate (includes equivalency)	$45,952	$41,528	$40,153
Some college or associate's degree	$47,694	$47,635	$47,260
Bachelor's degree	$59,375	$62,744	$70,044
Graduate or professional degree	$84,044	$80,022	$90,720
Poverty rates
Less than high school graduate	30.3%	21.5%	24.2%
High school graduate (includes equivalency)	6.6%	12.4%	14.4%
Some college or associate's degree	7.5%	8.1%	9.8%
Bachelor's degree or higher	2.7%	3.8%	4.5%

Insights for Grundy County, 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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