Gaithersburg, MD 20878 ZIP Code Profile

Related Place Profiles:
Darnestown, MD | Gaithersburg, MD | North Potomac, MD

ZIP Code 20878: Basic Data & USPS Preferred City Name

Preferred Name, USPS
Gaithersburg, MD 20878

Acceptable Alternative
Darnestown, MD 20878
N Potomac, MD 20878
No Potomac, MD 20878
North Potomac, MD 20878

  • ZIP Code Type: STANDARD
  • County: Montgomery County
  • Centroid: Latitude 39.106, Longitude -77.24
  • Time Zone: Eastern Time Zone (UTC -5 hours)
  • Observes DST: Yes
  • Businesses Addresses: 962
  • PO Box Addresses: 0
  • Residential Addresses: 24,059
    • Multi-Family Addresses: 6,575
    • Single Family Addresses: 17,484

The ZIP Code maps and database are updated 4 times per year.
Database updated: May 1, 2018, Maps updated: February 1, 2018.

EXTREMELY LOCAL Demographic Data

Address Based Hyperlocal Data Input an address and get data & demographics for the pertinent census block group (CBG), a searchable map and a customized directory. The CBG is the smallest geographical unit used by the Census Bureau for reporting demographic data.


20878 ZIP Code Map

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Gaithersburg, MD 20878 Data & Demographics (As of July 1, 2017)


Total Population 67,991
Daytime Population: Workers 35,564
Daytime Population: Residents 30,570
Total Daytime Population (TDP) 66,134
Ratio TDP/Total Population1 0.97
Population in Households 67,875
Population in Familes 58,211
Population in Group Qrtrs 116
Population Density2 3,536
Diversity Index3 73


Median Household Income $119,329
Average Household Income $151,065
Per Capita Income $54,137


Total Housing Units 24,958 (100%)
Owner Occupied HU 16,589 (66.5%)
Renter Occupied HU 7,749 (31.0%)
Vacant Housing Units 620 ( 2.5%)
Median Home Value $551,936
Average Home Value $580,174


Total Households 24,338
Average Household Size 2.79
Family Households 17,945
Average Family Size 3
  1. If the ratio of the TDP to Total Population is greater than 1, the location gains population during the day when commuting workers are present. If the ratio is less than 1, the location is more of a bedroom community where people commute to another place for work.
  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.


2010-2017 2017-2022
Population 1.2% 1.19%
Households 1.2% 1.21%
Families 0.95% 1.01%
Median Household Income   1.52%
Per Capita Income   1.98%

Gaithersburg, MD 20878 - Peer Comparisons by Rank and Percentile

The table below compares 20878 to the other 456 ZIP Codes in Maryland by rank and percentile using July 1, 2017 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 # 3 100th
Population Density # 68 85th
Diversity Index # 37 92nd
Median Household Income # 46 90th
Per Capita Income # 51 89th

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

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