St. Louis County, Missouri Demographics
Population trends, housing costs, income, commuting, and health, all on one page.
St. Louis County, 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 averageAmong the top 5 healthiest counties in Missouri
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B
Income Around averageAmong the top 3 wealthiest counties in Missouri
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A
Education Above averageBest educated county in Missouri
Source: Map AI Methodology
Population: density and quick facts
| Metric | St. Louis County | Missouri Avg | U.S. Average |
|---|---|---|---|
| Population | 995,111 | 6,186,340 | 337,468,954 |
| Population density (per sq mi) | 1900.6 | 88.8 | 86.4 |
| Population growth (%/yr) | -0.08% | 0.28% | 0.59% |
| Median age | 40.5 | 37.5 | 37.3 |
| Households | 413,654 | 2,507,647 | 130,235,071 |
Population in St. Louis County declined by 0.0% from 2009 to 2024, reaching 995,111 in 2024.
Population Growth 2009–2024
Race & Ethnicity
Age & Sex
The largest generation in St. Louis County is Millennials, aged 29–44, at 20.8% of residents. That is 0.4 points below Missouri as a whole.
- Gen Z 13–28 199,084 20.0% -1.2 pts
- Millennials 29–44 207,289 20.8% -0.4 pts
- Gen X 45–60 203,518 20.5% +0.8 pts
- Boomers 61–79 184,994 18.6% +0.7 pts
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 52.3% of the people living in St. Louis County and men 47.7%.
- Women 52.3% Missouri 50.7%
- Men 47.7% Missouri 49.3%
How many residents match a customer profile?
Residents matching this profile
100% of everyone living in St. Louis County
Pick an age range and a women/men split and the figure above answers with how many residents that profile reaches.
Economy
St. Louis County has a the economy index of B, which means it is quite prosperous.
| Metric | St. Louis County | Missouri Avg | U.S. Average |
|---|---|---|---|
| Median household income | $83,558 | $70,801 | $80,455 |
| Income growth (%/yr) | 3.97% | 4.56% | 4.80% |
| Unemployment rate | 4.3% | 4.0% | 5.2% |
The median household income in St. Louis County is about 18% higher than in Missouri.
Housing
| Metric | St. Louis County | Missouri Avg | U.S. Average |
|---|---|---|---|
| Median home price | $227,571 | $145,462 | $248,835 |
| Median rent | $1,208 | $1,033 | $1,407 |
| Homeownership rate | 69.2% | 68.1% | 65.2% |
The median home price in St. Louis County is about 15.7 years' worth of rent — buying at the median price costs roughly as much as paying the median rent of $1,208 per month for that long.
Commute Time & Mobility
Commuters in St. Louis County spend about 44 minutes on the road round trip each working day. Over a typical 250-day work year, that adds up to roughly 182 hours, about 7.6 full days, spent commuting.
| Metric | St. Louis County | Missouri Avg | U.S. Average |
|---|---|---|---|
| One-way commute (min) | 21.9 | 21.0 | 22.4 |
| Round-trip commute (min) | 43.7 | 41.9 | 44.8 |
| Yearly time spent (hours) | 182 | 175 | 187 |
| Estimated yearly cost | $5,648 | $5,415 | $5,790 |
| Work from home | 18.3% | 13.0% | 15.0% |
| Highway traffic (vehicles/day) | 16,020 | 7,545 | 8,813 |
| Local road traffic (vehicles/day) | 2,451 | 923 | 1,355 |
Fastest commutes among counties in
Missouri:
Saline County (11.9 min), Adair County (12.0 min), Nodaway County (12.1 min).
Slowest:
Bollinger County (33.1 min), Ray County (32.2 min), Maries County (31.9 min).
The average commute time in St. Louis County is 22 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
St. Louis County has a education index of A, which means it is very educated.
| Metric | St. Louis County | Missouri Avg | U.S. Average |
|---|---|---|---|
| Bachelor's degree or higher | 43.1% | 28.8% | 31.6% |
| Average household size | 2.36 | 2.40 | 2.53 |
Highest education index among counties in
Missouri:
St. Louis County (0.4), Platte County (0.4), Boone County (0.4).
Lowest:
Bollinger County (0.2), Wayne County (0.2), Ripley County (0.2).
Health
St. Louis County has a health index of B, which means it is quite healthy.
| Metric | St. Louis County | Missouri Avg | U.S. Average |
|---|---|---|---|
| Life expectancy (years) | 78.6 | 76.9 | 78.3 |
| Self-rated poor health | 14.6% | 19.0% | 16.3% |
| Smokers | 15.8% | 22.8% | 19.0% |
Highest health index among counties in
Missouri:
St. Charles County (0.8), Platte County (0.8), Boone County (0.8).
Lowest:
Scotland County (0.7), Ripley County (0.7), Pemiscot County (0.8).
St. Louis County, MO Compared With Nearby Counties
St. Louis County, MO is the largest of the 5 counties compared here, 995,111 residents against a local median of 132,240. The measure that sets St. Louis County, MO apart most is median home price: $227,571, 18% above the local median of $193,296.
The counties themselves spread $197,118 on median home price, so St. Louis County, MO sits at one end of an already wide local range rather than apart from it. St. Louis County, MO has the 2nd highest median home price of the 5 areas compared here.
| Area | Population | Median household income | Median home price | Commute |
|---|---|---|---|---|
| St. Louis County, MO | 995,111 | $83,558 #3/5 | $227,571 #2/5 | 21.9 min #1/5 |
| St. Charles County, MO | 414,008 | $105,635 | $326,504 | 22.7 min |
| Jefferson County, MO | 229,447 | $82,868 | $178,434 | 30.7 min |
| Monroe County, IL | 35,033 | $103,327 | $208,158 | 28.2 min |
| Jersey County, IL | 21,266 | $78,198 | $129,386 | 22.8 min |
Frequently Asked Questions
Common questions about St. Louis County, Missouri.
How big is St. Louis County, Missouri by population?
About 995,111 people live in St. Louis County, Missouri, in 413,654 households of 2.4 people on average. The median age is 40.5, so residents are older than the U.S. median of 37.3 by about 3 years.
Is St. Louis County, Missouri mostly urban or rural?
Averaged over its land area, St. Louis County, Missouri has 1,901 people per square mile, a density typical of urban and suburban areas. That is about 22 times the U.S. average of 86.
How affordable is housing in St. Louis County, Missouri?
The median home costs 2.7 times the median household income ($227,571 against $83,558), compared with 3.1 times nationally. That is within the traditional rule of thumb of about 3 times income. Median rent of $1,208 a month takes about 17% of the median household's income, below the 30% level at which HUD considers renters cost-burdened.
How common is a college degree in St. Louis County, Missouri?
43.1% of adults in St. Louis County, Missouri hold a bachelor's degree or higher (about 1 in 2), well above the U.S. share of 31.6%.
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