18104 ZIP Code, Allentown, PA

18104 is a ZIP code in Allentown, Pennsylvania in Lehigh County. It covers 23 square miles of land. The closest ZIP codes are 18106, 18069 and 18102. 48,683 people live here in 18,532 households, more than in 9 of every 10 Pennsylvania ZIP codes. At about 2,121 people per square mile it has suburban density, and most homes are owner-occupied (71%). Median household income is $94,601, above the Pennsylvania median of $77,971.

Quick facts

Key figures

MeasureValue
Residents48,683
Households18,532
Median household income$94,601
Income per person$46,691
Median age40.6
Homeowners71.0%
Median home value$336,400
Median rent$1,637
Bachelor's degree or higher46.1%
Average commute (minutes)21.5
Households with kids under 1828.4%
Moved in the past year9.2%
Below the poverty line8.3%
Broadband internet91.8%
Speak a non-English language at home20.0%

Household income

% of householdsValue
<$10K3.2%
$10–15K3.2%
$15–25K5.4%
$25–35K6.7%
$35–50K7.0%
$50–75K14.3%
$75–100K12.6%
$100–150K20.9%
$150–200K12.7%
$200K+14.1%

Age

% of all residentsValue
<1010.0%
10–1913.2%
20–247.5%
25–3412.0%
35–4413.9%
45–5411.2%
55–6411.6%
65–7410.4%
75+10.0%

Tenure

% of housing unitsValue
Owned, with mortgage44.2%
Owned outright25.0%
Rented27.4%
Vacant3.4%

Type of building

% of housing unitsValue
Detached house55.0%
Townhome21.9%
2–4 units5.5%
5–19 units9.1%
20+ units8.3%
Mobile / other0.2%

Businesses in 18104

1,248 business establishments with 25,626 employees (ZIP Codes Business Patterns 2023).

EDDM carrier routes

18104 has 48 USPS carrier routes with 19,434 residential and 1,177 business mailboxes. Open the EDDM route map.

Carrier routes in 18104

18104 has 48 USPS carrier routes (38 city (C), 10 rural (R)) with 19,434 residential and 1,177 business mailboxes. Routes range from 113 homes (R025) to 909 homes (R008); the median route has 394 homes. The Census counted 18,532 households in 18104 (2020–2024 average); USPS counts current mailboxes, including new and vacant homes.

Homes per routeRoutes
1–2496
250–49932
500–7498
750–9992
1,000–1,4990
1,500+0

Best routes in 18104 for…

Most businesses

For B2B offers: office supplies, cleaning, IT, catering and commercial services.

  1. Route C052 — USPS business mailboxes 107, 304 homes
  2. Route C017 — USPS business mailboxes 97, 177 homes
  3. Route C081 — USPS business mailboxes 96, 197 homes
  4. Route R011 — USPS business mailboxes 75, 596 homes
  5. Route C036 — USPS business mailboxes 75, 332 homes

Select these 5 routes on the route map

Every carrier route in 18104

RouteTypeHomesBusinessesEst. median incomeEst. ownersEst. families with kidsEst. moved in past year
C002City30515$66,673———
C003City39420$54,848———
C004City4217$77,979———
C005City4548$57,032———
C006City21819$77,979———
C012City30359$74,604———
C013City4070$85,998———
C015City2780$147,786———
C016City4062$87,186———
C017City17797$118,671———
C018City36813$105,574———
C019City32623$74,604———
C022City3412$77,945———
C036City33275$66,137———
C037City31240$67,888———
C043City3961$118,671———
C048City4212$147,786———
C050City3938$147,786———
C052City304107$19,210———
C054City3390$118,671———
C055City4973$60,713———
C058City3251$147,786———
C062City3536$93,927———
C066City55627$81,557———
C067City47516$66,673———
C072City39873$77,945———
C077City52314————
C081City19796$81,557———
C084City3426$67,888———
C090City3202$77,945———
C093City46616$87,186———
C094City23425$77,979———
C095City3161$154,528———
C098City61116$41,429———
C099City37311$127,136———
C100City24542$154,528———
C101City4631$105,574———
C103City5487$77,979———
R001Rural51113$67,658———
R003Rural4291$137,058———
R008Rural90918$110,464———
R011Rural59675$110,464———
R013Rural28363$127,136———
R017Rural45919$105,137———
R020Rural53110$110,464———
R022Rural6268$110,464———
R024Rural84051$81,557———
R025Rural11358$110,464———

Income, owners, families and movers are estimates for each route (how we estimate them); mailbox counts are current USPS figures. Open 18104 on the EDDM route map.

How route demographics are estimated

Mailbox counts come from USPS; demographics are estimates

The number of homes and businesses on each carrier route is the current USPS EDDM count. The Census Bureau does not publish figures for carrier routes, so income, homeownership, ages, families, movers and housing age on a route are EDDM2GO estimates built from Census block groups (neighborhood areas of roughly 600 to 3,000 people).

How a route gets its figures: the block-group length-share method

We trace each route's streets every 25 meters and record which block group each stretch falls in. The route's homes are spread along its streets in proportion to length, so a route with 60% of its street length in one block group is assumed to have 60% of its homes there. Each block group then contributes its Census counts in proportion to the share of its housing units that sit on the route (capped at the whole block group). Medians are recalculated from the combined income, home-value and age brackets, the way the Census Bureau computes them, not averaged.

Margins of error

Census survey figures carry a margin of error at 90% confidence; we carry it through the calculation and show it as ±. Our margins treat the route-to-block-group split as exact, so the real uncertainty is larger. Routes with fewer than 100 estimated households, large margins, or streets we could not place are flagged.

Different years

USPS mailbox counts are current. Census figures are 5-year averages for 2020–2024, so a new subdivision may have more homes on the route today than the Census counted. Use the route figures to compare routes with each other, not as an exact head count.

Why some routes show identical figures

Two routes that run through the same block group get the same percentages and medians, because the Census publishes one set of figures for the whole block group. Their mailbox counts still differ, and those are exact.

Route and mailbox counts: USPS EDDM route data. Route demographics: EDDM2GO estimates from U.S. Census Bureau American Community Survey 5-year block-group data (2020–2024) and 2024 cartographic block-group boundaries. This product uses the Census Bureau Data API but is not endorsed or certified by the Census Bureau.

Nearby ZIP codes

Areas that include 18104

Where it ranks

Mail every home in 18104

Route counts on this page price as Full Service 6.5 × 9 postcards: we print, bundle by carrier route and hand the mailing to USPS. Prefer to take it to the Post Office yourself? Print only costs less and you pay postage at drop-off.

EDDM guides

ZIP code statistics describe the Census ZIP Code Tabulation Area (ZCTA) 18104, which approximates the USPS ZIP code area. Census figures: American Community Survey 5-year estimates, 2020–2024.

Frequently asked questions

What city is 18104 in?
18104 is a Allentown, PA mailing address. By land area, 17% lies inside Allentown, 4% lies inside Cetronia, 2% lies inside Dorneyville and 1% lies inside Wescosville; the rest is outside any Census-defined city or community.
What county is 18104 in?
18104 is in Lehigh County.
What is the population of 18104?
About 48,683 people (±1,582), according to the Census Bureau's American Community Survey 5-year estimates for 2020–2024. The 2020 Census counted 47,289.
What is the median household income in 18104?
$94,601 (±$6,014), compared with $77,971 for Pennsylvania as a whole. Half the households in the ZIP code earn more and half earn less.
How many carrier routes and mailboxes are in 18104?
48 USPS carrier routes with 19,434 residential and 1,177 business mailboxes (20,612 in all), from the route data stored by EDDM2GO. An EDDM mailing can target any combination of these routes.
What ZIP codes are near 18104?
The closest, measured center to center: 18106 (3.4 mi, Wescosville), 18069 (3.7 mi), 18102 (3.7 mi, Allentown), 18052 (3.9 mi, Fullerton), 18101 (4.1 mi, Allentown) and 18103 (4.2 mi, Allentown).

This product uses the Census Bureau Data API but is not endorsed or certified by the Census Bureau.