Arnold, Missouri Demographics
Population trends, housing costs, income, commuting, and health, all on one page.
Arnold, MO Population Density Map and Area Scores
Area Score
Health, income and education, each graded from F to A+. Explore interactive maps for deeper analysis.
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B
Health Around average
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B
Income Around average
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D
Education Well below average
Source: Map AI Methodology
Population
| Metric | Arnold | Missouri Avg | U.S. Average |
|---|---|---|---|
| Population | 20,372 | 6,186,340 | 337,468,954 |
| Population density (per sq mi) | 1766.4 | 88.8 | 86.4 |
| Population growth (%/yr) | -0.32% | 0.28% | 0.59% |
| Median age | 40.1 | 37.5 | 37.3 |
| Households | 8,198 | 2,507,647 | 130,235,071 |
Population in Arnold grew by 6.2% from 2009 to 2024, reaching 20,372 in 2024.
Population Growth 2009–2024
Race & Ethnicity
Age & Sex
The largest generation in Arnold is Gen X, aged 45–60, at 22.1% of residents. That is 2.5 points above Missouri as a whole.
- Gen Z 13–28 3,964 19.5% -1.7 pts
- Millennials 29–44 4,329 21.3% on par
- Gen X 45–60 4,501 22.1% +2.5 pts
- Boomers 61–79 3,638 17.9% on par
Residents by birth cohort, from the 2025 age distribution. The right-hand figure is how far each cohort's share sits above or below Missouri, in percentage points. Children younger than Gen Z and the generations before the Boomers are counted in the population but not shown here, so these shares do not add up to 100%.
Male and female share
Women are 50.9% of the people living in Arnold and men 49.1%.
- Women 50.9% Missouri 50.7%
- Men 49.1% Missouri 49.3%
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Economy
Arnold has a the economy index of B, which means it is quite prosperous.
| Metric | Arnold | Missouri Avg | U.S. Average |
|---|---|---|---|
| Median household income | $79,652 | $70,801 | $80,455 |
| Income growth (%/yr) | 3.57% | 4.56% | 4.80% |
| Unemployment rate | 3.1% | 4.0% | 5.2% |
The median household income in Arnold is about 13% higher than in Missouri.
Housing
| Metric | Arnold | Missouri Avg | U.S. Average |
|---|---|---|---|
| Median home price | $228,354 | $145,462 | $248,835 |
| Median rent | $1,121 | $1,033 | $1,407 |
| Homeownership rate | 80.8% | 68.1% | 65.2% |
The median home price in Arnold is about 17.0 years' worth of rent — buying at the median price costs roughly as much as paying the median rent of $1,121 per month for that long.
Commute Time & Mobility
Commuters in Arnold spend about 55 minutes on the road round trip each working day. Over a typical 250-day work year, that adds up to roughly 230 hours, about 9.6 full days, spent commuting.
| Metric | Arnold | Missouri Avg | U.S. Average |
|---|---|---|---|
| One-way commute (min) | 27.6 | 21.0 | 22.4 |
| Round-trip commute (min) | 55.2 | 41.9 | 44.8 |
| Yearly time spent (hours) | 230 | 175 | 187 |
| Estimated yearly cost | $7,134 | $5,415 | $5,790 |
| Work from home | 9.0% | 13.0% | 15.0% |
| Highway traffic (vehicles/day) | 21,175 | 7,545 | 8,813 |
| Local road traffic (vehicles/day) | 2,757 | 923 | 1,355 |
The average commute time in Arnold is 28 minutes, longer than the 21 minutes in Missouri.
Estimated yearly cost applies a single national wage rule of thumb (U.S. Bureau of Labor Statistics average hourly earnings), not a measurement of wages in this area. Traffic volume figures come from proprietary Ticon and TrafficZoom data.
Education & Households
Arnold has a education index of D, which means it is barely educated.
| Metric | Arnold | Missouri Avg | U.S. Average |
|---|---|---|---|
| Bachelor's degree or higher | 22.3% | 28.8% | 31.6% |
| Average household size | 2.48 | 2.40 | 2.53 |
Health
Arnold has a health index of B, which means it is quite healthy.
| Metric | Arnold | Missouri Avg | U.S. Average |
|---|---|---|---|
| Life expectancy (years) | 76.9 | 76.9 | 78.3 |
| Self-rated poor health | 14.9% | 19.0% | 16.3% |
| Smokers | 21.5% | 22.8% | 19.0% |
Arnold, MO Compared With Nearby Cities
How Arnold, MO compares with the 2 cities closest to it.
| Area | Population | Median household income | Median home price | Commute |
|---|---|---|---|---|
| Arnold, MO | 20,372 | $79,652 #2/3 | $228,354 #2/3 | 27.6 min #2/3 |
| Oakville, MO | 35,902 | $105,992 | $291,985 | 28.6 min |
| Mehlville, MO | 29,047 | $69,104 | $109,514 | 22.9 min |
Frequently Asked Questions
Common questions about Arnold, Missouri.
What is the population of Arnold, Missouri?
About 20,372 people live in Arnold, Missouri, in 8,198 households of 2.5 people on average. The median age is 40.1, so residents are older than the U.S. median of 37.3 by about 3 years.
Is Arnold, Missouri mostly urban or rural?
Averaged over its land area, Arnold, Missouri has 1,766 people per square mile, a density typical of urban and suburban areas. That is about 20 times the U.S. average of 86.
Is Arnold, Missouri an affordable place to live?
The median home costs 2.9 times the median household income ($228,354 against $79,652), compared with 3.1 times nationally. That is within the traditional rule of thumb of about 3 times income. Median rent of $1,121 a month takes about 17% of the median household's income, below the 30% level at which HUD considers renters cost-burdened.
Is unemployment high in Arnold, Missouri?
Unemployment in Arnold, Missouri is only 3.1%, well below the U.S. rate of 5.2%, a sign of a tight labor market where employers compete for workers.
How common is a college degree in Arnold, Missouri?
22.3% of adults in Arnold, Missouri hold a bachelor's degree or higher (about 1 in 4), well below the U.S. share of 31.6%.
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