🇺🇸 United States ZIP Code

STANDARD

18109

Allentown

ZIP Code 18109 is a standard zip code serving Allentown, Allentown, Pennsylvania (PA), in Lehigh County, United States. It has an estimated population of 16,932 with a median household income of $38,506. The area falls within the America/New_York timezone.

Median Household Income vs. National Average

Location

Country: 🇺🇸 United States
State / Province: Pennsylvania (PA)
County: Lehigh
City: Allentown
Timezone: America/New_York

Coordinates

Latitude: 40.636600
Longitude: -75.440500

Geographic Details

Land Area: 8.20 mi²
Water Area: 0.25 mi²
Population Density: 2066.0 people per mi² (85th percentile)
Bounding Box: 40.683063°N, 40.597500°S, -75.409343°E, -75.465323°W

With 16,932 residents spread across 8.20 square miles, this area has a population density of 2066.0 people per square mile.

Demographics

16,932

Population

75th percentile

$38,506

Median Income

25th percentile

$141,500

Median Home Value

55th percentile

8.20 mi²

Land Area

The median household income in 18109 is $38,506, and the median home value is $141,500. This is below the national average for household income.

Housing

7,269

Total Units

6,655

Occupied Units

91.6%

Occupancy Rate

Nearby ZIP Codes

Other zip codes in Allentown, PA.

18101

Allentown

18102

Allentown

18103

Allentown

18104

Allentown

18105

Allentown

18106

Allentown

18195

Allentown

Similar ZIP Codes in Pennsylvania

ZIP codes with similar median household income in Pennsylvania.

16920

Elkland

$40,139

15853

Ridgway

$43,246

17847

Milton

$43,484

15865

Sykesville

$33,534

17051

Mc Veytown

$43,234

15851

Reynoldsville

$41,161

16001

Butler

$43,968

18640

Pittston

$44,152

Frequently Asked Questions

What information is available for each ZIP code?

Each ZIP code page shows city, state, county, geographic coordinates, timezone, population, median household income, median home value, housing units, land area, population density, commute time, educational attainment, area codes, and ZIP code type (Standard, PO Box, or Unique).

What are the different types of ZIP codes?

There are three types of ZIP codes: Standard (residential and commercial delivery areas), PO Box (assigned to post office box sections), and Unique (assigned to a single high-volume address like a government agency or large company). Standard ZIP codes are the most common.

How often is ZIP code data updated?

ZIP code assignments are updated quarterly by the USPS. Demographic data comes from the US Census Bureau's American Community Survey (ACS), which releases new 5-year estimates annually. ZipFYI updates its data to reflect the latest available information.

What is population density and why does it matter?

Population density measures the number of people per square mile in a ZIP code area. It helps identify urban vs. rural areas, affects real estate values, impacts service availability, and is used in market analysis. Dense urban ZIP codes may have 50,000+ people per square mile.

How are ZIP code boundaries determined?

ZIP code boundaries are determined by the USPS based on mail delivery routes, not political or geographic boundaries. They follow carrier routes and may cross city, county, or even state lines. Boundaries can change when the USPS reorganizes delivery operations.

What does median household income tell me about a ZIP code?

Median household income is the middle value when all household incomes in a ZIP code are sorted. Half of households earn more and half earn less. It is a better indicator of typical earnings than average income, which can be skewed by very high or very low outliers.