Allentown, PA

ZIP code 18104 is assigned to Allentown, PA, and falls within Lehigh County. Like every US postal code, it began as a mail-routing device rather than a geographic boundary — the US Postal Service groups delivery routes under a single code so carriers and sorting equipment can process mail efficiently. Today it also serves as a practical shorthand for the area itself: roughly 47,999 people live inside it.

At 2,091 residents per square mile spread over 22.952 square miles, 18104 reads as a suburban area. It is a populous postal code, and density shapes almost everything else on this page — how people get to work, whether they own or rent, and what housing costs.

Household earnings run above the national median. At $94,279, 18104 sits comfortably in the upper half, ahead of 79% of them. The US median for comparison is $70,109. Bear in mind that median income describes the midpoint household, not the average — it is not pulled upward by a handful of very high earners the way a mean would be.

Housing in 18104 costs close to the national median. A typical home is valued at $296,800 against a US median of $207,500, and median gross rent runs $1,620 a month. The split between owning and renting is fairly even at 69.6% owner-occupied, which tends to indicate a mix of housing types rather than one dominant form.

The building stock is dominated by detached single-family houses, which account for 76.5% of housing units here. The median construction year is 1971, making the housing here from the later twentieth century. At 2.9%, vacancy is low — housing here is tightly held.

The population skews broadly in line with the national age profile, with a median age of 39.3 against 42 nationally. The average household holds 2.65 people, and 63.8% are family households.

Getting to work takes 23.5 minutes on average one way. The dominant mode is drove alone at 70.6% of workers, while 17.5% work from home. Commute patterns are one of the better proxies for how a place actually functions day to day.

Beyond addressing mail, 18104 does a lot of quiet administrative work. Retailers use it to calculate shipping and sales tax at checkout. Insurers use it to set premiums, since risk profiles vary geographically. Employers and marketers use it to define service areas. Government agencies use it to route benefits and organise reporting. If you have ever been asked for a postal code by a form that clearly does not intend to send you anything, this is why.

For anyone weighing a move, 18104 offers a compact profile of Allentown: 47,999 residents, a median household income of $94,279, 44.8% of adults holding a bachelor's degree or higher, and an unemployment rate of 5.5%. A handful of figures like these answer more relocation questions than most neighbourhood guides do.

One caution worth repeating: a postal code is not a neighbourhood. 18104 may cover parts of several distinct areas, and a single neighbourhood in Allentown may be split across more than one code. Boundaries also shift as USPS adjusts delivery routes. Treat the figures here as describing a delivery area, which is what they actually measure.