Mount Airy, MD 21771 ZIP Code Profile


ZIP Code 21771: Basic Data & USPS Preferred City Name

Preferred Name, USPS
Mount Airy, MD 21771

  • ZIP Code Type: STANDARD
  • County: Frederick County
  • Centroid: Latitude 39.388, Longitude -77.148
  • Time Zone: Eastern Time Zone (UTC -5 hours)
  • Observes DST: Yes

ZIP Code 21771 has segments in 4 Counties / Independent Cities (Carroll, Frederick, Howard, Montgomery).

  • Businesses Addresses: 733
  • PO Box Addresses: 335
  • Residential Addresses: 10,638
    • Multi-Family Addresses: 105
    • Single Family Addresses: 10,533

The ZIP Code maps and database are updated 4 times per year.
Database updated: February 1, 2019, Maps updated: February 1, 2019.

Jump to... (On This Page!)
  1. 21771 2018 Demographic Data
  2. Growth Rates for 21771 (Historical & 5-Year Forecast)
  3. Peer Comparisons (Rank and Percentile)
  1. Neighborhoods Demographics (Home Values, Household Income, etc.)
  2. Maryland Research Tools (Easy Tools & Current Data)
  3. Maryland Data Comparison Tool - 2018 Demographics

Popular Places Near ZIP Code 21771

Research a Maryland Address and get...

Boundary Maps, Demographic Data, School Zones Review maps and data for the neighborhood, city, county, ZIP Code, and school zone. July 1, 2018, data includes home values, household income, percentage of homes owned, rented or vacant, etc.


Mount Airy, MD 21771 Data & Demographics (As of July 1, 2018)


Total Population 30,237
Population in Households 30,062
Population in Familes 27,251
Population in Group Qrtrs 175
Population Density2 356
Diversity Index3 25


Median Household Income $110,281
Average Household Income $134,674
Per Capita Income $45,058


Total Housing Units 10,440 (100%)
Owner Occupied HU 9,048 (86.7%)
Renter Occupied HU 1,021 ( 9.8%)
Vacant Housing Units 371 ( 3.6%)
Median Home Value $431,958
Average Home Value $469,339


Total Households 10,069
Average Household Size 2.99
Family Households 8,228
Average Family Size 3
  1. Demographics are point estimates for July 1st of the current year and each for the forecast years. See References for more information.
  2. Population Density = Total Population per square mile.
  3. 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 race 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.


2010-2018 2018-2023
Population 0.48% 0.66%
Households 0.48% 0.66%
Families 0.38% 0.59%
Median Household Income   1.49%
Per Capita Income   2.61%

Mount Airy, MD 21771 - Peer Comparisons by Rank and Percentile

The table below compares 21771 to the other 448 ZIP Codes in Maryland by rank and percentile using July 1, 2018 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.

Variable Description Rank Percentile
Total Population # 80 82nd
Population Density # 235 48th
Diversity Index # 334 25th
Median Household Income # 91 80th
Per Capita Income # 131 71st

Additional comparisons and rankings can be made with a VERY EASY TO USE Maryland Census Data Comparison Tool.

Quick & Easy Ways to...

  1. Get Current Demographic Data for Cities, Towns, and ZIP Codes
  2. View Boundary Maps, for Cities, Towns, and ZIP Codes
  3. Locate Physical, Cultural, and Historical Features
  4. Research Public Schools & Attendance Zones

Maryland Census Data Comparison Tool

Compare Maryland July 1, 2018 Data
Highest or Lowest: