18109 ZIP Code Profile, Map, Data & Demographics

ZIP Code Type: STANDARD
County: Lehigh County
Centroid: Latitude 40.581, Longitude -75.472
Time Zone: Eastern Time Zone (UTC -5 hours)
Observes DST: Yes

ZIP Code 18109 has segments in 2 Counties (Lehigh, Northampton).

Businesses Addresses: 1,101
PO Box Addresses: 164
Residential Addresses: 7,362

Multi-Family Addresses: 916
Single Family Addresses: 6,446

The ZIP Code maps and database are updated 4 times per year.
Database updated: June 1, 2025, Maps updated: May 1, 2024.

Allentown, PA 18109 Data & Demographics (As of July 1, 2025)

POPULATION
Total Population	19,340 (100%)
Population in Households	19,219 (99.4%)
Population in Families	15,360 (79.4%)
Population in Group Quarters¹	121 ( 0.6%)
Population Density	2,053
Diversity Index²	86


INCOME
Median Household Income	$56,253
Average Household Income	$74,749
% of Income for Mortgage⁴	25%
Per Capita Income	$28,782
Wealth Index⁵	48
Socioeconomic Status Index⁶	Low (38.6)

HOUSING
Total HU (Housing Units)	7,766 (100%)
Owner Occupied HU	3,862 (49.7%)
Renter Occupied HU	3,563 (45.9%)
Vacant Housing Units	341 ( 4.4%)
Median Home Value	$221,100
Average Home Value	$299,836
Housing Affordability Index³	86

HOUSEHOLDS
Total Households	7,425
Average Household Size	2.59
Family Households	4,677
Average Family Size	3.00

NOTES

Group Quarters - a place where people live or stay in a group living arrangement. Includes college residents halls, nursing facilities, military barracks, and correctional facilities.
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 races 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.
The Housing Affordability Index base is 100 and represents a balance point where a resident with a median household income can normally qualify to purchase a median price home. Values above 100 indicate increased affordability, while values below 100 indicate decreased affordability.
The % of Income for Mortgage quantifies the percentage of median household income dedicated to mortgage payments on a home priced at the median value (assuming a 30-year mortgage and a 20% down payment).
The Wealth Index is based on a number of indicators of affluence including average household income and average net worth, but it also includes the value of material possessions and resources. It represents the wealth of the area relative to the national level. Values above or below 100 represent above-average wealth or below-average wealth compared to the national level.
The Socioeconomic Index ranges from zero (lowest relative status) to 100 (highest relative status). This measure quantifies disparities in social position of an area's inhabitants and is built from a broad range of demographic, housing, and socioeconomic inputs. More information on this measure can be found in Esri's SEI tutorial.

Allentown, PA 18109 - Peer Comparisons by Rank and Percentile

The table below compares 18109 to the other 1,696 ZIP Codes in Pennsylvania by rank and percentile using July 1, 2025 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.

GROWTH RATE / YEAR	2020-2025	2025-2030
Population	0.25%	0.26%
Households	0.37%	0.31%
Families		0.28%
Median Household Income		1.81%
Per Capita Income		1.89%
Owner Occupied HU		0.93%

Variable Description	Rank	Percentile
Total Population	# 213	88th
Population Density	# 265	84th
Median Household Income	# 1443	15th
Housing Affordability Index	# 462	27th
Per Capita Income	# 1474	13th
Diversity Index	# 6	100th

18109 ZIP Code Profile, Map, Data & Demographics

ZIP Code 18109: Basic Data & USPS Preferred City Name

Allentown, PA 18109 Data & Demographics (As of July 1, 2025)

POPULATION

INCOME

HOUSING

HOUSEHOLDS

GROWTH RATE / YEAR

Allentown, PA 18109 - Peer Comparisons by Rank and Percentile

Popular Places Near ZIP Code 18109

Use HTL Address Research for a Pennsylvania Address and get...

Quick & Easy Ways to...

Pennsylvania Census Data Comparison Tool

More Tools and Resources:

Lehigh County