What city is 18109 in?

18109 is a Allentown, PA mailing address. By land area, 44% lies inside Allentown; the rest is outside any Census-defined city or community.

What is the population of 18109?

About 18,446 people (±1,395), according to the Census Bureau's American Community Survey 5-year estimates for 2020–2024. The 2020 Census counted 18,915.

What is the median household income in 18109?

$58,031 (±$4,767), 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 18109?

15 USPS carrier routes with 7,391 residential and 1,057 business mailboxes (8,445 in all), from the route data stored by EDDM2GO. An EDDM mailing can target any combination of these routes.

What ZIP codes are near 18109?

The closest, measured center to center: 18032 (2 mi, Catasauqua borough, PA), 18018 (2.5 mi, Bethlehem), 18102 (2.6 mi, Allentown), 18101 (2.7 mi, Allentown), 18017 (3.3 mi, Bethlehem) and 18052 (3.6 mi, Fullerton).

18109 ZIP Code, Allentown, PA

Q: What county is 18109 in?

18109 is mostly in Lehigh County (95% of its land), with smaller parts in Northampton County.

18109 is a ZIP code in Allentown, Pennsylvania — mostly in Lehigh County (95% of its land), with smaller parts in Northampton County. It covers 8.2 square miles of land. The closest ZIP codes are 18032, 18018 and 18102. 18,446 people live here in 7,030 households. At about 2,236 people per square mile it has suburban density, and owners and renters are mixed (52% own). Median household income is $58,031, below the Pennsylvania median of $77,971.

Quick facts

Mailing city: Allentown, PA
County: Lehigh County
Land area: 8.2 sq mi
Population: 18,446
Median household income: $58,031
Carrier routes: 15 (7,391 homes)

Key figures

Measure	Value
Residents	18,446
Households	7,030
Median household income	$58,031
Income per person	$28,396
Median age	36.6
Homeowners	52.1%
Median home value	$198,800
Median rent	$1,331
Bachelor's degree or higher	16.0%
Average commute (minutes)	23.3
Households with kids under 18	32.8%
Moved in the past year	10.3%
Below the poverty line	18.1%
Broadband internet	88.2%
Speak a non-English language at home	51.3%

Household income

% of households	Value
<$10K	4.8%
$10–15K	4.6%
$15–25K	13.1%
$25–35K	5.5%
$35–50K	14.4%
$50–75K	24.4%
$75–100K	10.0%
$100–150K	12.5%
$150–200K	7.7%
$200K+	2.9%

Age

% of all residents	Value
<10	13.3%
10–19	12.8%
20–24	6.7%
25–34	16.0%
35–44	15.6%
45–54	9.8%
55–64	11.1%
65–74	8.1%
75+	6.7%

Tenure

% of housing units	Value
Owned, with mortgage	31.1%
Owned outright	18.0%
Rented	44.5%
Vacant	6.5%

Type of building

% of housing units	Value
Detached house	34.2%
Townhome	32.6%
2–4 units	8.5%
5–19 units	16.3%
20+ units	6.4%
Mobile / other	2.0%

Businesses in 18109

802 business establishments with 17,337 employees (ZIP Codes Business Patterns 2023).

Health Care and Social Assistance: 103
Retail Trade: 92
Other Services (except Public Administration): 84
Accommodation and Food Services: 79
Wholesale Trade: 77
Administrative and Support and Waste Management and Remediation Services: 56
Manufacturing: 55
Transportation and Warehousing: 54

EDDM carrier routes

18109 has 15 USPS carrier routes with 7,391 residential and 1,057 business mailboxes. Open the EDDM route map.

Carrier routes in 18109

18109 has 15 USPS carrier routes (13 city (C), 2 rural (R)) with 7,391 residential and 1,057 business mailboxes. Routes range from 37 homes (R018) to 777 homes (C042); the median route has 508 homes. The Census counted 7,030 households in 18109 (2020–2024 average); USPS counts current mailboxes, including new and vacant homes.

Homes per route	Routes
1–249	2
250–499	5
500–749	7
750–999	1
1,000–1,499	0
1,500+	0

Best routes in 18109 for…

Most businesses

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

Route R018 — USPS business mailboxes 208, 37 homes
Route R004 — USPS business mailboxes 174, 230 homes
Route C061 — USPS business mailboxes 159, 261 homes
Route C020 — USPS business mailboxes 84, 488 homes
Route C018 — USPS business mailboxes 84, 379 homes

Select these 5 routes on the route map

Every carrier route in 18109

Route	Type	Homes	Businesses	Est. median income	Est. owners	Est. families with kids	Est. moved in past year
C018	City	379	84	$47,942	—	—	—
C019	City	641	34	$41,898	—	—	—
C020	City	488	84	$69,825	—	—	—
C023	City	537	59	$61,957	—	—	—
C029	City	748	19	$56,370	—	—	—
C042	City	777	45	$41,058	—	—	—
C057	City	508	63	$66,915	—	—	—
C061	City	261	159	$47,942	—	—	—
C073	City	546	5	$73,295	—	—	—
C074	City	485	44	$47,942	—	—	—
C086	City	427	23	$61,957	—	—	—
C091	City	702	27	$63,667	—	—	—
C093	City	625	29	$47,942	—	—	—
R004	Rural	230	174	$53,057	—	—	—
R018	Rural	37	208	$66,915	—	—	—

Income, owners, families and movers are estimates for each route (how we estimate them); mailbox counts are current USPS figures. Open 18109 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

18032 — Catasauqua borough, PA (2 mi)
18018 — Bethlehem city, PA (2.5 mi)
18102 — Allentown city, PA (2.6 mi)
18101 — Allentown city, PA (2.7 mi)
18017 — Bethlehem city, PA (3.3 mi)
18052 — Fullerton CDP, PA (3.6 mi)
18103 — Allentown city, PA (5.1 mi)
18015 — Bethlehem city, PA (5.2 mi)

Areas that include 18109

Where it ranks

Mail every home in 18109

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) 18109, which approximates the USPS ZIP code area. Census figures: American Community Survey 5-year estimates, 2020–2024.

Frequently asked questions

What city is 18109 in?: 18109 is a Allentown, PA mailing address. By land area, 44% lies inside Allentown; the rest is outside any Census-defined city or community.
What county is 18109 in?: 18109 is mostly in Lehigh County (95% of its land), with smaller parts in Northampton County.
What is the population of 18109?: About 18,446 people (±1,395), according to the Census Bureau's American Community Survey 5-year estimates for 2020–2024. The 2020 Census counted 18,915.
What is the median household income in 18109?: $58,031 (±$4,767), 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 18109?: 15 USPS carrier routes with 7,391 residential and 1,057 business mailboxes (8,445 in all), from the route data stored by EDDM2GO. An EDDM mailing can target any combination of these routes.
What ZIP codes are near 18109?: The closest, measured center to center: 18032 (2 mi, Catasauqua borough, PA), 18018 (2.5 mi, Bethlehem), 18102 (2.6 mi, Allentown), 18101 (2.7 mi, Allentown), 18017 (3.3 mi, Bethlehem) and 18052 (3.6 mi, Fullerton).

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