The ZIP code 18103 in Allentown, Pennsylvania, covers an area of 17.3 square miles and had a population of 47,078 in 2022, resulting in a population density of 2,721.27 people per square mile. This population density falls within the suburban classification, indicating a lifestyle that is family-oriented with good access to schools, parks, and shopping centers. The area likely features a mix of residential types and denser developments, with lot sizes varying from 0.25 to 1 acre, promoting an active community life through sports leagues, homeowners associations, and local festivals.

Looking at the historical population data from 2010 to 2022, the population in this ZIP code has remained relatively stable, with minor fluctuations. The population increased from 45,071 in 2010 to 47,790 in 2021, before slightly decreasing to 47,078 in 2022. The population density has followed a similar trend, increasing from 2,605.26 people per square mile in 2010 to 2,762.43 in 2021, before decreasing to 2,721.27 in 2022. These numbers suggest that the area has experienced a modest level of urban development activity over the past decade, with a slight slowdown in recent years.