St. Mary's County MD Data & Demographics (As of July 1, 2021)
POPULATION
Total Population
117,231 (100%)
Population in Households
114,440 (97.6%)
Population in Families
95,639 (81.6%)
Population in Group Quarters1
2,791 ( 2.4%)
Population Density
328
Diversity Index2
47
INCOME
Median Household Income
$88,186
Average Household Income
$112,823
% of Income for Mortgage4
16%
Per Capita Income
$40,745
Wealth Index5
138
HOUSING
Total HU (Housing Units)
47,337 (100%)
Owner Occupied HU
31,282 (66.1%)
Renter Occupied HU
11,003 (23.2%)
Vacant Housing Units
5,052 (10.7%)
Median Home Value
$335,068
Average Home Value
$379,502
Housing Affordability Index3
142
HOUSEHOLDS
Total Households
42,285
Average Household Size
2.71
Family Households
29,992
Average Family Size
3
NOTES
Group Quarters - a place where people live or stay in a group living arrangement. Includes college residents halls, nursing facilities, military barracks, and correctional facilities.
The Diversity Index is a scale of 0 to 100 that represents the likelihood that two persons, chosen at random from the same area, belong to different races or ethnic groups. If an area's entire population belongs to one race AND one ethnic group, then the area has zero diversity. An area's diversity index increases to 100 when the population is evenly divided into two or more race/ethnic groups.
The Housing Affordability Index base is 100 and represents a balance point where a resident with a median household income can normally qualify to purchase a median price home. Values above 100 indicate increased affordability, while values below 100 indicate decreased affordability.
The % of Income for Mortgage quantifies the percentage of median household income dedicated to mortgage payments on a home priced at the median value (assuming a 30-year mortgage and a 20% down payment).
The Wealth Index is based on a number of indicators of affluence including average household income and average net worth, but it also includes the value of material possessions and resources. It represents the wealth of the area relative to the national level. Values above or below 100 represent above-average wealth or below-average wealth compared to the national level.
GROWTH RATE / YEAR
2010-2021
2021-2026
Population
0.97%
0.84%
Households
1.05%
0.88%
Families
0.91%
0.78%
Median Household Income
1.67%
Per Capita Income
2.04%
Owner Occupied HU
1.18%
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St. Mary's County MD - Peer Comparisons by Rank and Percentile
The table below compares St. Mary's County to the other 24 counties / independent cities and county equivalents in Maryland by rank and percentile using July 1, 2021 data. The location Ranked # 1 has the highest value. A location that ranks higher than 75% of its peers would be in the 75th percentile of the peer group.
