PlainZIP

Conowingo, MD · standard

ZIP Code 21918

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

4,284
94/sq mi
$84,587
Median income
$324,800
Median home value
16.1%
Bachelor's or higher

The verdict

Conowingo pairs an above-median household income with above-median home values, in a rural, homeowner-dominated area.

Top 32%
household income, US ZIPs
Top 30%
home value, US ZIPs
94
people per sq mi
89%
owner-occupied homes

Source: U.S. Census Bureau ACS 5-Year Estimates (2019–2023). Percentiles rank ZIP 21918 against every reporting US ZIP.

ZIP code 21918 covers 45.7 square miles in Conowingo, Cecil County, Maryland (a standard USPS delivery area), with a modest 4,284 residents on file, a density of 94 people per square mile, in the New York time zone.

ZIP 21918 lands in the middle-income range, with a median household income of $84,587 (26% below the Maryland average), while per-capita income is $47,697. The poverty rate stands at 6.1% and the unemployment rate at 3.1%. The typical home here is valued at $324,800 (27% below the state average); renters pay a median of $876 monthly, and 88.6% of units are owner-occupied.

Educational attainment sits below the national norm: 16.1% of adults hold a bachelor's degree or higher, the median age is 42.9, and the average commute is 36 minutes. To put 21918 in local context, 10 ZIP codes within roughly 10 miles appear further down this page alongside 6 additional ZIPs in Cecil County, for a geography-aware comparison.

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 21918

Top 5 sectors by establishment count in Conowingo, MD

Which industries have the most business establishments in ZIP 21918.

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 21918, Conowingo, 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

4,284

Population

45.7

Area (sq mi)

94

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 21918?

42.9

Median Age

50.9%

Male

49.1%

Female

0.3%

Foreign-Born

White 88.3%
African American 2.0%
Asian 0.3%
American Indian or Alaska Native 0.1%
Native Hawaiian or Pacific Islander 0.0%
Two or More Ethnicities 8.9%
Hispanic or Latino 2.8%

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?

$84,587

Median Household Income

-26% vs state

$47,697

Per Capita Income

6.1%

Poverty Rate

3.1%

Unemployment Rate

35.6 min

Mean Commute Time

How ZIP 21918 ranks nationally

Conowingo, MD household income vs. every US ZIP code

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

$84,587 Top 32% higher than 68% 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%). This entry sits in this band. $100,000–$120,000: 2,855 US ZIPs (9%). Above this entry. $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 53.6%
Bachelor's Degree or Higher 16.1%

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

What does housing look like?

1,815

Total Housing Units

1,775

Occupied Units

40

Vacant Units

2.34

Avg Household Size

Occupancy Type

Owner 88.6%
Renter 11.4%

$324,800

Median Home Value

-27% vs state

$876

Median Rent

1987

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

-8.4%

YoY Change (2024)

225

HPI Index (2000 = 100)

+125%

Total Change Since 2000

Home values in ZIP 21918 have decreased 8.4% over the past year (2024). Since 2000, this ZIP has seen +125% cumulative appreciation.

Year Annual Change HPI Index
2020 +2.6% 179
2021 +13.6% 204
2022 +11.5% 227
2023 +8.4% 246
2024 -8.4% 225

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 48 business establishments in ZIP 21918, employing approximately 260 people with a combined annual payroll of $10,747,000.

48

Businesses

260

Employees

$10.7M

Annual Payroll

9

Industry Sectors

Industry Establishments % of Total
Construction 10 20.8%
Other services (except public administration) 7 14.6%
Retail trade 6 12.5%
Wholesale trade 4 8.3%
Transportation and warehousing 4 8.3%
Real estate and rental and leasing 4 8.3%
Administrative and support and waste management and remediation services 3 6.3%
Health care and social assistance 3 6.3%
Accommodation and food services 3 6.3%

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 21918 vs 21917 →

ZIP 21918 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 21918 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 21918 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 21918 ranks #9 of 9 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
21917 Colora, MD 2,520 3.7 mi
21034 Darlington, MD 3,387 3.7 mi
17563 Peach Bottom, PA 3,849 5.7 mi
21078 Havre De Grace, MD 17,603 8.0 mi
21911 Rising Sun, MD 11,004 6.8 mi
21904 Port Deposit, MD 7,252 6.3 mi
21160 Whiteford, MD 2,408 7.8 mi
19362 Nottingham, PA 5,815 7.1 mi
21028 Churchville, MD 3,460 8.9 mi
17518 Drumore, PA 1,355 9.7 mi

More ZIP Codes in Cecil County

21921 standard
Elkton, MD
Pop: 44,471
21901 standard
North East, MD
Pop: 15,875
21911 standard
Rising Sun, MD
Pop: 11,004
21904 standard
Port Deposit, MD
Pop: 7,252
21903 standard
Perryville, MD
Pop: 5,687
21919 standard
Earleville, MD
Pop: 3,467

Related Areas

Cecil County Conowingo, MD Maryland

Frequently Asked Questions

What county is ZIP code 21918 in? ▼
ZIP code 21918 (Conowingo) is located in Cecil County, Maryland. Cecil County contains multiple ZIP codes, see the full list at /counties/cecil-md.
What is the population of ZIP code 21918? ▼
ZIP code 21918 in Conowingo, MD has a population of 4,284 according to the Census Bureau ACS 2023 estimates.
What is the median household income in ZIP 21918? ▼
The median household income in ZIP 21918 is $84,587, which is 11% above the national average of $76,288.
What is the average home value in ZIP 21918? ▼
The median home value in ZIP 21918 is $324,800, which is 17% above the national average of $278,155.
What is the demographic makeup of ZIP 21918? ▼
The largest racial group in ZIP 21918 is White at 88.3%. Hispanic or Latino residents make up 2.8% of the population.
How many businesses are in ZIP code 21918? ▼
ZIP code 21918 has 48 business establishments employing approximately 260 people, according to Census Bureau ZIP Code Business Patterns (ZBP) 2023 data.
What are the main industries in ZIP code 21918? ▼
The top industries by establishment count in ZIP 21918 are: Construction (10), Other services (except public administration) (7), Retail trade (6). There are 9 industry sectors represented in total.
How have home values changed in ZIP code 21918? ▼
According to the FHFA House Price Index, home values in ZIP 21918 decreased by 8.4% in 2024. Since 2000, home values in this ZIP have appreciated by approximately 125%. 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 21918? ▼
In ZIP code 21918, 53.6% of residents aged 25+ have a high school diploma or higher, and 16.1% 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 21918? ▼
The mean commute time for workers in ZIP code 21918 is 35.6 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 21918? ▼
In ZIP code 21918, approximately 88.6% of occupied housing units are owner-occupied and 11.4% are renter-occupied, based on Census ACS 2023 data.
What is the poverty rate in ZIP code 21918? ▼
The poverty rate in ZIP code 21918 is 6.1% 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.