Every ZIP code in the United States, with weather, radar, trivia and the numbers behind it. Five digits since 1963!

ZIP stands for Zone Improvement Plan. The codes went live on July 1, 1963.The lowest ZIP code is 00501 — the IRS in Holtsville, New York.The highest ZIP code is 99950, in Ketchikan, Alaska.Type 07734 into a calculator and turn it upside down: hELLO. It is Keansburg, New Jersey.12345 belongs to one company: General Electric in Schenectady, New York.The first digit is a region: 0 is New England and New Jersey, 9 is the West Coast, Alaska and Hawaii.Mr. ZIP, the cartoon mailman, was the mascot that sold the idea to America.ZIP+4 arrived in 1983 and can narrow a ZIP down to one side of one block.A ZIP code is a mail route, not a place: plenty of them cross county and even state lines.Play ZIP Hunt: guess the secret ZIP code of the day in six tries.
zipcodes.pro — ZIP/15421

15421

ZIP 15421 is Chalk Hill, Pennsylvania, in Fayette County; area codes 724 and 878; Eastern time.

Type
Standard
Time zone
America/New_York
County
Fayette
Metro area
Pittsburgh, PA
Population
207
Coordinates
39.8452, -79.5974
☼ Live from 15421 — Chalk Hill, PA

Weather right now

Asking the National Weather Service…

NEXRAD radar
Finding the nearest radar…
Local time: —

Where 15421 is

Approximate ZIP boundary (Census ZCTA 2020). ZIP codes are mail routes, not areas, so the shape shown is the Census tabulation area that approximates it.

★ Weird and wonderful facts about 15421
  • 🔢 Type 15421 into a pocket calculator and turn it upside down: IZhSI — not quite a word, sorry.
  • ➕ As a number, 15,421 = 7 × 2203. Its digits add up to 13, a total 1,179 other ZIP codes share.
  • 💾In binary, the way a computer stores it: 11110000111101
  • 🏠 Its numerical neighbours: 15420 (Cardale, PA, 16 mi away) and 15422 (Chestnut Ridge, PA, 15 mi away).
  • 🔄 Backwards, 15421 becomes 12451 — and that is a real ZIP code: Leeds, NY, 340 miles away.
  • 👥 33 other ZIP codes are made of exactly the same digits (11245, 11425, 11542, 12154, 12451, 12514, …). The farthest-flung twin is 51241 in Larchwood, IA, 904 miles away.
  • 🧭 Farther north than 55% of all ZIP codes, and farther east than 75%.
  • 🎯1,005 miles east of the geographic center of the Lower 48, near Lebanon, Kansas.
  • 🌏 Dig straight through the Earth from 15421 and you would come out at 39.85°S, 100.40°E — 1,020 miles from Perth, Australia, the nearest big city to that spot.
  • ☀Longest day of the year: 15h 00m of daylight. Shortest: 9h 20m.
  • 📏 At 0.268 square miles of land, 15421 is bigger than 3% of ZIP codes — about 130 football fields.
🌙 The sky over 15421 today
  • Working out the sun…
🌋 Shake report
  • Checking the USGS…

Source: USGS.

People and housing

Population207This ZIP207
Households79This ZIP79
Housing units154This ZIP154
Median age61.6This ZIP61.6Pennsylvania40.9US 38.9
Median household income$250,000+This ZIP$250,000+Pennsylvania$77,971US $80,734
Median home value$222,500This ZIP$222,500Pennsylvania$254,500US $332,700
Bachelor's degree or higher80.0%This ZIP80.0%
Population density772.4 / sq miThis ZIP772.4 / sq mi

Business and tax activity

Business establishments17This ZIP17
Employees145This ZIP145
Annual payroll$6,034,000This ZIP$6,034,000

Land area

Land area0.27 sq miThis ZIP0.27 sq mi
Water area0.00 sq mi

Other place names in 15421

Census places whose land this ZIP code overlaps. The Postal Service may accept other city names in an address, too.

ZIP codes near 15421

ZIPCityDistance
15470 Ohiopyle, PA 3.5 mi
15437 Farmington, PA 3.5 mi
15445 Hopwood, PA 4.3 mi
15431 Dunbar, PA 6.1 mi
15456 Lemont Furnace, PA 6.3 mi
15416 Brownfield, PA 6.7 mi
15465 Mount Braddock, PA 6.9 mi
15436 Fairchance, PA 7.0 mi
15440 Gibbon Glade, PA 7.8 mi
15472 Oliver, PA 8.1 mi

Find every ZIP code within 10 miles of 15421 →

Questions about this ZIP code

Where is ZIP code 15421?

15421 is in Chalk Hill, Pennsylvania, in Fayette County, part of the Pittsburgh, PA metropolitan area. Its published point location is 39.8452, -79.5974.

What county is 15421 in?

15421 lies in Fayette County.

What area code is 15421?

Chalk Hill uses area codes 724 and 878, from NANPA's telephone records.

What time zone is 15421 in?

15421 uses America/New_York.

How many people live in 15421?

About 207 people live in ZIP code 15421, in 79 households, at 772.4 people per square mile. These are American Community Survey 5-year estimates for the ZIP Code Tabulation Area, not a headcount.

What is the median household income in 15421?

$250,000+ a year, against $77,971 across Pennsylvania.

What ZIP codes are near 15421?

The closest are 15470 (3.5 mi), 15437 (3.5 mi), 15445 (4.3 mi), 15431 (6.1 mi) and 15456 (6.3 mi).

Is 15421 a PO Box ZIP code?

15421 is a standard ZIP code. A normal ZIP code with street delivery.

Download or cite

Cite this page

zipcodes.pro. “15421 ZIP Code — Chalk Hill, Pennsylvania (Fayette County).” Data release 2026-10-12. Retrieved 2026-10-20. https://zipcodes.pro/zip/15421

Machine-readable version of these facts:

curl https://zipcodes.pro/zip/15421.json

Underlying data is public domain or openly licensed — sources, vintages and licences.