Arnold, Missouri Demographics & Population 2026
During the 2020–2024 ACS period, Arnold, Missouri had a total population of 20,956, the 36th largest city in Missouri, with a median household income of $78,370, which is 11% higher than the state average. The poverty rate is 8.2%.
Data vintage: U.S. Census Bureau ACS 2020–2024 5-Year Estimates · refreshed July 2026 · Methodology & source notes
Arnold Quick Facts
How Arnold Changed
Change from the 2019–2023 ACS period to 2020–2024. These are rolling five-year estimates, not year-over-year measurements.
| Metric | 2019–2023 | 2020–2024 | Change |
|---|---|---|---|
| Population | 20,884 | 20,956 | +0.3% |
| Median household income | $75,194 | $78,370 | +4.2% |
| Median home value | $209,700 | $220,000 | +4.9% |
How Arnold Compares
Median Household Income
Median Home Value
Economy & Housing
Household Income Distribution
Detailed income brackets
Employment
Housing Overview
People & Demographics
Age Distribution
Race & Ethnicity
Diversity Index
A less diverse community where one racial or ethnic group represents a large majority.
State average: 40 | National average: 61
Education
Educational Attainment (Adults 25+)
Arnold Rankings in Missouri
Explore Missouri Rankings
Other Cities in Jefferson County
| City | Population | Median Income | Poverty | Home Value |
|---|---|---|---|---|
| Festus | 13,201 | $73,532 | 17.1% | $223,600 |
| Murphy | 8,285 | $72,233 | 10.2% | $184,700 |
| De Soto | 6,470 | $52,500 | 13.1% | $160,700 |
| Pevely | 6,055 | $56,000 | 17.9% | $219,600 |
| Barnhart | 5,785 | $95,811 | 4.9% | $229,200 |
| Imperial | 5,488 | $90,028 | 11.1% | $228,700 |
| Herculaneum | 5,071 | $93,438 | 5.6% | $234,300 |
| Crystal City | 4,718 | $72,598 | 11.4% | $185,800 |
| High Ridge | 3,714 | $70,917 | 7.2% | $172,200 |
| Hillsboro | 3,500 | $77,500 | 11.7% | $221,200 |
Cities Similar to Arnold
These cities in the same state have comparable population and economic profiles.
| City | Population | Median Income | Home Value | Bachelor's+ | Poverty |
|---|---|---|---|---|---|
| Ozark | 22,417 | $74,182 | $254,800 | 30.8% | 12.6% |
| Affton | 19,052 | $79,539 | $212,400 | 36.6% | 6.7% |
| Old Jamestown | 20,651 | $99,521 | $236,100 | 39.6% | 7.4% |
| Republic | 19,829 | $65,729 | $211,500 | 26.3% | 17.7% |
| Concord | 18,368 | $89,038 | $303,600 | 42.0% | 3.9% |
Population Overview
Arnold is a small city located in Missouri, within Jefferson County. The total population is 20,956. It ranks as the 36th most populous out of 1,062 Census-designated places in Missouri.
Age Demographics
The median age in Arnold is 39.7 years. This is 2% higher than the state median of 39.0 years.
Economy, Income & Housing
The median household income in Arnold is $78,370. This is 11% higher than the state median of $70,702. It is also 3% lower than the national median of $80,734. The poverty rate stands at 8.2%. This is 35% lower than the state poverty rate of 12.6%. The unemployment rate is 2.8%. This is 30% lower than the state rate of 4.0%. The median home value is $220,000. Housing costs are 4% lower than the state median of $230,300. With a home-value-to-income ratio of just 2.8x, Arnold is one of the most affordable housing markets in the area. 79.8% of occupied housing units are owner-occupied. This homeownership rate is 17% higher than the state average of 68.1%.
Race & Ethnicity
Arnold has a predominantly White (non-Hispanic) population, comprising 88.0% of all residents. Hispanic or Latino residents account for 2.6%. The Black or African American population (0.3%) is well below the state average of 10.9%.
Education
25.4% of residents aged 25 and older hold a bachelor's degree or higher. This is 22% lower than the state rate of 32.4%. Nationally, 35.7% of adults hold at least a bachelor's degree. The high school graduation rate (or equivalent) is 90.6%.
Data Sources & Methodology
All demographic data for Arnold, Missouri is sourced from the U.S. Census Bureau's American Community Survey (ACS) 2020–2024 5-Year Estimates. The ACS collects data from approximately 3.5 million households annually and pools five years of responses so that even small communities can be measured, though the margin of error widens as the population falls. Comparisons are made against Missouri state averages and national averages calculated from the same dataset. Rankings reflect the city's position among all 1,062 Census-designated places in Missouri. Read more about how these figures are produced on our methodology page, or visit data.census.gov for official data.
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Frequently Asked Questions
What is the population of Arnold, Missouri?
Arnold, Missouri has a population of 20,956 according to the most recent U.S. Census ACS 5-Year Estimates.
What is the median household income in Arnold, MO?
The median household income in Arnold is $78,370, which is 3% lower than the national median of $80,734.
What is the poverty rate in Arnold, MO?
The poverty rate in Arnold is 8.2%. This means approximately 1,698 residents live below the federal poverty line.
What is the racial makeup of Arnold, Missouri?
Arnold's population is 88.0% White, 0.3% Black, 2.6% Hispanic/Latino, and 1.8% Asian.
What is the median home value in Arnold, MO?
The median home value in Arnold is $220,000. The home-value-to-income ratio is 2.8x.
How educated is Arnold, Missouri?
25.4% of adults (25+) in Arnold hold a bachelor's degree or higher, and 8.1% hold a graduate or professional degree.