🇺🇸 United States ZIP Code

STANDARD

18101

Allentown

ZIP Code 18101 is a standard zip code serving Allentown, Allentown, Pennsylvania (PA), in Lehigh County, United States. It has an estimated population of 3,897 with a median household income of $17,250. 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: 40.602600
Longitude: -75.469100

Geographic Details

Land Area: 0.35 mi²
Population Density: 11166.0 people per mi² (95th percentile)
Bounding Box: 40.609505°N, 40.596929°S, -75.456751°E, -75.482230°W

With 3,897 residents spread across 0.35 square miles, this area has a population density of 11166.0 people per square mile.

Demographics

3,897

Population

50th percentile

$17,250

Median Income

$102,800

Median Home Value

35th percentile

0.35 mi²

Land Area

The median household income in 18101 is $17,250, and the median home value is $102,800.

Housing

1,821

Total Units

1,540

Occupied Units

84.6%

Occupancy Rate

Nearby ZIP Codes

Other zip codes in Allentown, PA.

18102

Allentown

18103

Allentown

18104

Allentown

18105

Allentown

18106

Allentown

18109

Allentown

18195

Allentown

Similar ZIP Codes in Pennsylvania

ZIP codes with similar median household income in Pennsylvania.

16503

Erie

$21,008

19104

Philadelphia

$19,236

18503

Scranton

$15,724

19133

Philadelphia

$14,185

15213

Pittsburgh

$21,928

15219

Pittsburgh

$20,151

19602

Reading

$21,795

15110

Duquesne

$20,152

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.