Zip Code 18103 — Allentown, PA

ZIP Code 18103 is associated with Allentown, PA, in Lehigh County. The listed population estimate is 48,746; estimated density is 1,096.9 people per square mile. Among records with population estimates, it ranks #2 of 27 in Lehigh County and #26 of 1,811 in PA.
Page generated: 2026-10-08. This is not the source data release date.

📍 View location on OpenStreetMap (40.572230, -75.481380)

Data MetricLocal Statistic
Postal / Zip Code18103
Primary CityAllentown
State / ProvincePA
CountyLehigh
Total Population48,746
Population Density1,096.9 people/sq mi
TimezoneAmerica/New_York

How 18103 Compares

MetricZIP 18103Lehigh County recordsPA records
Population estimate48,746386,389 (sum)13,018,637 (sum)
Population Density1,096.9 /sq mi----
County population rank#2 of 27----
State population rank#26 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 18101Allentown2.2 mi6,120
ZIP 18102Allentown2.5 mi51,001
ZIP 18049Emmaus3.8 mi18,941
ZIP 18034Center Valley4.0 mi9,209
ZIP 18104Allentown4.4 mi48,683

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 →