Zip Code 18109 — Allentown, PA

ZIP Code 18109 is associated with Allentown, PA, in Lehigh County. The listed population estimate is 18,446; estimated density is 863.5 people per square mile. Among records with population estimates, it ranks #8 of 27 in Lehigh County and #223 of 1,811 in PA.
Page generated: 2026-10-08. This is not the source data release date.

📍 View location on OpenStreetMap (40.636730, -75.440430)

Data MetricLocal Statistic
Postal / Zip Code18109
Primary CityAllentown
State / ProvincePA
CountyLehigh
Total Population18,446
Population Density863.5 people/sq mi
TimezoneAmerica/New_York

How 18109 Compares

MetricZIP 18109Lehigh County recordsPA records
Population estimate18,446386,389 (sum)13,018,637 (sum)
Population Density863.5 /sq mi----
County population rank#8 of 27----
State population rank#223 of 1,811----

Regional sums combine the population estimates in the listed ZIP records; they are not official county or state population totals.

Explore More ZIP Codes

Nearby ZIP Codes in PA

ZIP CodeCityDistancePopulation estimate
ZIP 18032Catasauqua2.0 mi9,555
ZIP 18018Bethlehem2.4 mi32,965
ZIP 18102Allentown2.7 mi51,001
ZIP 18101Allentown2.8 mi6,120
ZIP 18017Bethlehem3.2 mi40,640

Data Sources & Methodology: Geographic coordinates and ZIP Code assignments are derived from underlying geographic and postal datasets. Note that ZIP Codes are USPS postal delivery areas, while Census ZCTAs are statistical approximation areas. Read full methodology →