PlainZIP

Keymar, MD · standard

ZIP Code 21757

Frederick County, Maryland - Census ACS demographics, housing tenure, and business patterns, benchmarked against every US ZIP.

3,036
31/sq mi
$100,500
Median income
$466,100
Median home value
29.5%
Bachelor's or higher

The verdict

Keymar pairs an upper-quartile household income with upper-quartile home values, in a rural, homeowner-dominated area.

Top 19%
household income, US ZIPs
Top 15%
home value, US ZIPs
31
people per sq mi
82%
owner-occupied homes

Source: U.S. Census Bureau ACS 5-Year Estimates (2019–2023). Percentiles rank ZIP 21757 against every reporting US ZIP.

ZIP code 21757 covers 97.6 square miles in Keymar, Frederick County, Maryland (a standard USPS delivery area), with a modest 3,036 residents on file, a density of 31 people per square mile, in the New York time zone.

ZIP 21757 lands in the middle-income range, with a median household income of $100,500 (12% below the Maryland average), while per-capita income is $46,390. 1.7% of residents live below the poverty line, and the unemployment rate reads 3.2%. The typical home here is valued at $466,100 (4% above the state average); renters pay a median of $1,408 monthly, and 82.4% of units are owner-occupied.

Educational attainment sits below the national norm: 29.5% of adults hold a bachelor's degree or higher, the median age is 37.8, and the average commute is 31 minutes. A geography-based comparison follows: 7 ZIP codes within about 10 miles of 21757, plus 6 more within Frederick County, give a clearer read than the national average alone.

Every figure on this page is sourced from the U.S. Census Bureau American Community Survey 5-Year Estimates (including median rent) and the FHFA House Price Index, no estimates, no proprietary scoring. Verify with Census →

Top industries in ZIP 21757

Top 5 sectors by establishment count in Keymar, MD

Which industries have the most business establishments in ZIP 21757.

establishments

What this shows Establishment counts come from the Census ZIP Code Business Patterns program, which counts physical business locations rather than employees or revenue.

Source U.S. Census Bureau · ZIP Code Business Patterns (ZBP) As of 2023

Source: U.S. Census Bureau, American Community Survey 5-Year Estimates + ZIP Code Business Patterns + FHFA HPI ACS demographics and median rent, ZBP business establishments, FHFA HPI for ZIP 21757, Keymar, MD · 2023 Census ACS 5-Year Estimates use a rolling 60-month sample for stable small-geography estimates; ZBP updated annually; FHFA HPI updated quarterly/annually.

Quick Facts

3,036

Population

97.6

Area (sq mi)

31

People / sq mi

New York

Time Zone

standard

ZIP Type

Neighborhood Scorecard
Get an A-F grade across income, safety, housing, rent, education, commute, and childcare for this ZIP code.
View Scorecard →

Who lives in ZIP 21757?

37.8

Median Age

55.0%

Male

45.0%

Female

4.3%

Foreign-Born

White 90.6%
African American 1.0%
Asian 2.2%
American Indian or Alaska Native 2.0%
Native Hawaiian or Pacific Islander 0.0%
Two or More Ethnicities 3.9%
Hispanic or Latino 2.4%

Hispanic or Latino is an ethnicity category from the Census Bureau and may overlap with other categories above.

Source: U.S. Census Bureau, ACS 5-Year Estimates (2023)

How much do residents earn?

$100,500

Median Household Income

-12% vs state

$46,390

Per Capita Income

1.7%

Poverty Rate

3.2%

Unemployment Rate

31.4 min

Mean Commute Time

How ZIP 21757 ranks nationally

Keymar, MD household income vs. every US ZIP code

Median household income, the full national distribution, with this ZIP marked

$100,500 Top 19% higher than 81% of 30,318 US ZIPs

$0–$20,000: 118 US ZIPs (0%). Below this entry. $20,000–$40,000: 1,573 US ZIPs (5%). Below this entry. $40,000–$60,000: 7,092 US ZIPs (23%). Below this entry. $60,000–$80,000: 9,980 US ZIPs (33%). Below this entry. $80,000–$100,000: 5,778 US ZIPs (19%). Below this entry. $100,000–$120,000: 2,855 US ZIPs (9%). This entry sits in this band. $120,000–$140,000: 1,362 US ZIPs (4%). Above this entry. $140,000–$160,000: 686 US ZIPs (2%). Above this entry. $160,000–$180,000: 364 US ZIPs (1%). Above this entry. $180,000–$200,000: 186 US ZIPs (1%). Above this entry. $200,000–$220,000: 324 US ZIPs (1%). Above this entry. This ZIP $0 $200K+ every reporting US ZIP, bucketed by value

Each bar is a $20K-wide band; taller bars hold more US ZIPs. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count, share, and where it sits relative to this entry.

Source U.S. Census Bureau, ACS 5-Year Estimates · 2019–2023

Source: U.S. Census Bureau, ACS 5-Year Estimates (2023)

What is the education profile here?

High School Graduate or Higher 67.1%
Bachelor's Degree or Higher 29.5%

Source: U.S. Census Bureau, ACS 5-Year Estimates (2023)

What does housing look like?

1,072

Total Housing Units

1,018

Occupied Units

54

Vacant Units

2.60

Avg Household Size

Occupancy Type

Owner 82.4%
Renter 17.6%

$466,100

Median Home Value

+4% vs state

$1,408

Median Rent

1962

Median Year Built

Source: U.S. Census Bureau, ACS 5-Year Estimates (2023)

How have home values changed over time?

FHFA House Price Index, annual appreciation data based on repeat sales and appraisals

+6.2%

YoY Change (2024)

255

HPI Index (2000 = 100)

+155%

Total Change Since 2000

Home values in ZIP 21757 have increased 6.2% over the past year (2024). Since 2000, this ZIP has seen +155% cumulative appreciation.

Year Annual Change HPI Index
2020 +9.9% 191
2021 +3.4% 198
2022 +17.8% 233
2023 +3.0% 240
2024 +6.2% 255

Source: Federal Housing Finance Agency (FHFA) House Price Index, All-Transactions, Five-Digit ZIP Codes (Developmental Index). Index base = 100 in year 2000. Data through 2024. ZIP codes with few transactions may show missing values.

What businesses operate in this ZIP?

Census Bureau data shows 64 business establishments in ZIP 21757, employing approximately 457 people with a combined annual payroll of $24,356,000.

64

Businesses

457

Employees

$24.4M

Annual Payroll

8

Industry Sectors

Industry Establishments % of Total
Construction 16 25.0%
Other services (except public administration) 11 17.2%
Transportation and warehousing 7 10.9%
Professional, scientific, and technical services 7 10.9%
Retail trade 5 7.8%
Manufacturing 4 6.3%
Administrative and support and waste management and remediation services 4 6.3%
Wholesale trade 3 4.7%

Source: U.S. Census Bureau, ZIP Code Business Patterns (ZBP), 2023. Employment figures may include noise for disclosure avoidance.

Nearby ZIP Codes

Want a side-by-side? Compare 21757 vs 21778 →

ZIP 21757 vs its nearest neighbors, by population

Resident population of this ZIP and the closest reporting ZIP codes within ~10 miles.

residents

What this shows Among its immediate neighbors, ZIP 21757 ranks #5 by population - useful context the national average alone can't give.

Source U.S. Census Bureau · ACS 5-Year Estimates As of 2019–2023

ZIP 21757 vs its nearest neighbors, by median income

Median household income of this ZIP and the closest reporting ZIP codes within ~10 miles.

median income

What this shows By household income, ZIP 21757 ranks #3 of 7 neighboring ZIPs, local affluence varies block to block, not just metro to metro.

Source U.S. Census Bureau · ACS 5-Year Estimates As of 2019–2023
ZIP Code City Population Distance
21778 Rocky Ridge, MD 1,094 4.4 mi
21798 Woodsboro, MD 2,345 5.0 mi
21762 Libertytown, MD 249 8.2 mi
21791 Union Bridge, MD 5,281 5.6 mi
21727 Emmitsburg, MD 5,850 7.2 mi
21787 Taneytown, MD 10,693 6.9 mi
21793 Walkersville, MD 9,775 8.9 mi

More ZIP Codes in Frederick County

21702 standard
Frederick, MD
Pop: 38,847
21701 standard
Frederick, MD
Pop: 35,293
21703 standard
Frederick, MD
Pop: 32,854
21771 standard
Mount Airy, MD
Pop: 29,563
21704 standard
Frederick, MD
Pop: 13,321
21774 standard
New Market, MD
Pop: 11,662

Related Areas

Frederick County Keymar, MD Maryland

Frequently Asked Questions

What county is ZIP code 21757 in? ▼
ZIP code 21757 (Keymar) is located in Frederick County, Maryland. Frederick County contains multiple ZIP codes, see the full list at /counties/frederick-md.
What is the population of ZIP code 21757? ▼
ZIP code 21757 in Keymar, MD has a population of 3,036 according to the Census Bureau ACS 2023 estimates.
What is the median household income in ZIP 21757? ▼
The median household income in ZIP 21757 is $100,500, which is 32% above the national average of $76,288.
What is the average home value in ZIP 21757? ▼
The median home value in ZIP 21757 is $466,100, which is 68% above the national average of $278,155.
What is the demographic makeup of ZIP 21757? ▼
The largest racial group in ZIP 21757 is White at 90.6%. Hispanic or Latino residents make up 2.4% of the population.
How many businesses are in ZIP code 21757? ▼
ZIP code 21757 has 64 business establishments employing approximately 457 people, according to Census Bureau ZIP Code Business Patterns (ZBP) 2023 data.
What are the main industries in ZIP code 21757? ▼
The top industries by establishment count in ZIP 21757 are: Construction (16), Other services (except public administration) (11), Transportation and warehousing (7). There are 8 industry sectors represented in total.
How have home values changed in ZIP code 21757? ▼
According to the FHFA House Price Index, home values in ZIP 21757 increased by 6.2% in 2024. Since 2000, home values in this ZIP have appreciated by approximately 155%. This is a developmental index based on repeat sales and appraisal data from Fannie Mae and Freddie Mac.
What is the education level in ZIP code 21757? ▼
In ZIP code 21757, 67.1% of residents aged 25+ have a high school diploma or higher, and 29.5% hold a bachelor's degree or higher. These figures come from the Census Bureau ACS 5-Year Estimates (2023).
What is the average commute time in ZIP 21757? ▼
The mean commute time for workers in ZIP code 21757 is 31.4 minutes according to Census ACS data. The national average is roughly 26 minutes, so commuters here spend more time traveling to work than typical.
What percentage of residents own vs. rent in ZIP 21757? ▼
In ZIP code 21757, approximately 82.4% of occupied housing units are owner-occupied and 17.6% are renter-occupied, based on Census ACS 2023 data.
What is the poverty rate in ZIP code 21757? ▼
The poverty rate in ZIP code 21757 is 1.7% according to Census Bureau ACS 2023 estimates. This measures the percentage of the population living below the federal poverty threshold.

Read our methodology to see how this data is sourced, computed, and verified.