St. Mary's County, MD Population Statistics: Density Map Data
Analyze local population trends, population density map, housing costs, and the local economy.
Area Snapshot Statistics
Key statistics on population, economy, housing, and commuting compared to state and national averages. Explore interactive maps for deeper analysis.
Population: density and quick facts
| Metric | St. Mary's County | Maryland Avg | U.S. Average |
|---|---|---|---|
| Population | 115,352 | 6,103,597 | 334,821,731 |
| Population density (per sq mi) | 151.0 | 492.0 | 85.8 |
| Population growth (%/yr) | 0.47% | 0.50% | 0.57% |
| Median age | 38.7 | 37.9 | 37.1 |
| Households | 41,743 | 2,338,890 | 128,459,983 |
Population in St. Mary's County grew by 14.2% from 2009 to 2023, reaching 114,372 in 2023.
Population Growth 2009–2023
Race & Ethnicity
Economy
St. Mary's County has a the economy index of B, which means it is quite prosperous.
| Metric | St. Mary's County | Maryland Avg | U.S. Average |
|---|---|---|---|
| Median household income | $115,463 | $101,971 | $78,145 |
| Income growth (%/yr) | 4.25% | 4.27% | 5.07% |
| Unemployment rate | 3.7% | 4.9% | 5.2% |
The median household income in St. Mary's County is about 13% higher than in Maryland.
Housing
| Metric | St. Mary's County | Maryland Avg | U.S. Average |
|---|---|---|---|
| Median home price | $359,433 | $285,029 | $242,182 |
| Median rent | $1,692 | $1,661 | $1,342 |
| Homeownership rate | 72.6% | 67.5% | 65.1% |
The median home price in St. Mary's County is about 17.7 years' worth of rent — buying at the median price costs roughly as much as paying the median rent of $1,692 per month for that long.
Commute Time & Mobility
Commuters in St. Mary's County spend about 45 minutes on the road round trip each working day. Over a typical 250-day work year, that adds up to roughly 188 hours, about 7.8 full days, spent commuting.
| Metric | St. Mary's County | Maryland Avg | U.S. Average |
|---|---|---|---|
| One-way commute (min) | 22.6 | 28.8 | 22.5 |
| Round-trip commute (min) | 45.2 | 57.5 | 44.9 |
| Yearly time spent (hours) | 188 | 240 | 187 |
| Estimated yearly cost | $5,833 | $7,433 | $5,803 |
| Work from home | 15.3% | 17.2% | 13.4% |
| Highway traffic (vehicles/day) | 8,343 | 16,437 | 8,813 |
| Local road traffic (vehicles/day) | 1,273 | 2,353 | 1,355 |
Fastest commutes among counties in
Maryland:
Allegany County (17.5 min), Wicomico County (17.8 min), Talbot County (18.3 min).
Slowest:
Charles County (41.7 min), Calvert County (35.3 min), Prince George's County (32.6 min).
The average commute time in St. Mary's County is 23 minutes, shorter than the 29 minutes in Maryland.
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. Mary's County has a education index of B, which means it is quite educated.
| Metric | St. Mary's County | Maryland Avg | U.S. Average |
|---|---|---|---|
| Bachelor's degree or higher | 32.5% | 39.3% | 31.6% |
| Average household size | 2.68 | 2.58 | 2.54 |
Highest education index among counties in
Maryland:
Howard County (0.5), Montgomery County (0.5), Talbot County (0.4).
Lowest:
Somerset County (0.2), Caroline County (0.2), Allegany County (0.2).
Health
St. Mary's County has a health index of B, which means it is quite healthy.
| Metric | St. Mary's County | Maryland Avg | U.S. Average |
|---|---|---|---|
| Life expectancy (years) | 80.8 | 78.4 | 78.3 |
| Self-rated poor health | 11.5% | 13.2% | 16.3% |
| Smokers | 16.7% | 15.9% | 19.0% |
Highest health index among counties in
Maryland:
Montgomery County (0.8), Howard County (0.8), Frederick County (0.8).
Lowest:
Baltimore city (0.8), Somerset County (0.8), Dorchester County (0.8).
Frequently Asked Questions
Common questions about St. Mary's County, Maryland.
What is the population of St. Mary's County, Maryland?
The population of St. Mary's County, Maryland is 115,352, compared to the U.S. total of 334,821,731.
What is the population density of St. Mary's County, Maryland?
The population density of St. Mary's County, Maryland is 151.0 people per square mile, compared to the U.S. average of 85.8 people per square mile.
What is the median household income in St. Mary's County, Maryland?
The median household income in St. Mary's County, Maryland is $115,463, compared to the U.S. median of $78,145.
What is the median home price in St. Mary's County, Maryland?
The median home price in St. Mary's County, Maryland is $359,433, compared to the U.S. median of $242,182.
What is the unemployment rate in St. Mary's County, Maryland?
The unemployment rate in St. Mary's County, Maryland is 3.7%, compared to the U.S. average of 5.2%.