18103 ZIP Code, Allentown, PA

18103 is a ZIP code in Allentown, Pennsylvania in Lehigh County. It covers 17 square miles of land. The closest ZIP codes are 18101, 18102 and 18049. 48,746 people live here in 18,880 households, which puts it among the most populous 1% of Pennsylvania ZIP codes. At about 2,841 people per square mile it has suburban density, and owners and renters are mixed (63% own). Median household income is $72,895, close to the Pennsylvania median of $77,971.

Quick facts

Key figures

MeasureValue
Residents48,746
Households18,880
Median household income$72,895
Income per person$40,738
Median age39.1
Homeowners63.1%
Median home value$272,700
Median rent$1,368
Bachelor's degree or higher27.6%
Average commute (minutes)24.5
Households with kids under 1832.4%
Moved in the past year14.8%
Below the poverty line10.3%
Broadband internet90.9%
Speak a non-English language at home37.7%

Household income

% of householdsValue
<$10K2.7%
$10–15K2.5%
$15–25K6.7%
$25–35K6.9%
$35–50K13.1%
$50–75K19.9%
$75–100K13.7%
$100–150K15.1%
$150–200K7.2%
$200K+12.2%

Age

% of all residentsValue
<1013.1%
10–1911.9%
20–246.1%
25–3415.1%
35–4411.1%
45–5412.2%
55–6413.3%
65–749.6%
75+7.7%

Tenure

% of housing unitsValue
Owned, with mortgage38.9%
Owned outright22.2%
Rented34.5%
Vacant4.4%

Type of building

% of housing unitsValue
Detached house52.4%
Townhome22.8%
2–4 units6.8%
5–19 units13.0%
20+ units4.5%
Mobile / other0.3%

Businesses in 18103

1,044 business establishments with 28,576 employees (ZIP Codes Business Patterns 2023).

EDDM carrier routes

18103 has 43 USPS carrier routes with 19,345 residential and 1,066 business mailboxes. Open the EDDM route map.

Carrier routes in 18103

18103 has 43 USPS carrier routes (40 city (C), 3 rural (R)) with 19,345 residential and 1,066 business mailboxes. Routes range from 154 homes (C031) to 865 homes (C015); the median route has 463 homes. The Census counted 18,880 households in 18103 (2020–2024 average); USPS counts current mailboxes, including new and vacant homes.

Homes per routeRoutes
1–2494
250–49922
500–74916
750–9991
1,000–1,4990
1,500+0

Best routes in 18103 for…

Most businesses

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

  1. Route C031 — USPS business mailboxes 105, 154 homes
  2. Route C033 — USPS business mailboxes 91, 220 homes
  3. Route C021 — USPS business mailboxes 84, 391 homes
  4. Route C058 — USPS business mailboxes 79, 169 homes
  5. Route C040 — USPS business mailboxes 68, 505 homes

Select these 5 routes on the route map

Every carrier route in 18103

RouteTypeHomesBusinessesEst. median incomeEst. ownersEst. families with kidsEst. moved in past year
C001City5522$119,306———
C007City60811$85,652———
C008City50820$53,626———
C009City4895$100,286———
C010City3391$126,315———
C015City8655$52,698———
C017City69035$53,003———
C021City39184$119,306———
C024City5100$123,268———
C028City7271$53,393———
C030City5013$27,392———
C031City154105$87,385———
C032City4632$50,659———
C033City22091$75,138———
C037City4246$50,171———
C039City5823$75,138———
C040City50568$100,286———
C045City54530$119,306———
C046City2662$126,315———
C053City38127$100,606———
C056City39819$70,638———
C058City16979$87,385———
C060City55615$76,862———
C063City56239$52,698———
C065City36361$123,268———
C066City46732$75,138———
C068City35639$53,626———
C071City4160$126,315———
C072City37518$100,286———
C075City49828$54,235———
C083City26121$100,286———
C084City34215$75,138———
C085City37726$81,557———
C089City5495$54,235———
C090City4179$100,286———
C095City22665$95,794———
C096City60524$53,003———
C098City6015$70,638———
C100City53642$53,626———
C101City4814$54,517———
R002Rural33710$168,115———
R007Rural4188$158,391———
R015Rural3151$168,115———

Income, owners, families and movers are estimates for each route (how we estimate them); mailbox counts are current USPS figures. Open 18103 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 18103

Where it ranks

Mail every home in 18103

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) 18103, which approximates the USPS ZIP code area. Census figures: American Community Survey 5-year estimates, 2020–2024.

Frequently asked questions

What city is 18103 in?
18103 is a Allentown, PA mailing address. By land area, 40% lies inside Allentown, 10% lies inside Dorneyville and 5% lies inside Wescosville; the rest is outside any Census-defined city or community.
What county is 18103 in?
18103 is in Lehigh County.
What is the population of 18103?
About 48,746 people (±2,105), according to the Census Bureau's American Community Survey 5-year estimates for 2020–2024. The 2020 Census counted 48,358.
What is the median household income in 18103?
$72,895 (±$4,130), 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 18103?
43 USPS carrier routes with 19,345 residential and 1,066 business mailboxes (20,411 in all), from the route data stored by EDDM2GO. An EDDM mailing can target any combination of these routes.
What ZIP codes are near 18103?
The closest, measured center to center: 18101 (2.5 mi, Allentown), 18102 (2.7 mi, Allentown), 18049 (3.3 mi, Emmaus borough, PA), 18106 (4 mi, Wescosville), 18046 (4.1 mi) and 18034 (4.2 mi, DeSales University).

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