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/21204

21204

ZIP 21204 is in Towson, Maryland, in Baltimore County; area codes 410, 443 and 667; Eastern time. Towson has 5 ZIP codes; the others are 21252, 21284, 21285 and 21286.

Type
Standard
Time zone
America/New_York
County
Baltimore
Population
19,845
Coordinates
39.4064, -76.6261
☼ Live from 21204 — Towson, MD

Weather right now

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NEXRAD radar
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Local time: —

Where 21204 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 21204
  • 🔢 Type 21204 into a pocket calculator and turn it upside down: hOZIZ — not quite a word, sorry.
  • ➕ As a number, 21,204 = 2 × 2 × 3 × 3 × 19 × 31. Its digits add up to 9, a total 375 other ZIP codes share.
  • 💾In binary, the way a computer stores it: 101001011010100
  • 🏠 Its numerical neighbours: 21203 (Baltimore, MD, 8 mi away) and 21205 (Baltimore, MD, 8 mi away).
  • 🔄 Backwards, 21204 becomes 40212 — and that is a real ZIP code: Louisville, KY, 500 miles away.
  • 👥 43 other ZIP codes are made of exactly the same digits (01224, 01242, 02124, 02142, 02241, 02421, …). The farthest-flung twin is 42021 in Arlington, KY, 695 miles away.
  • 🧭 Farther north than 52% of all ZIP codes, and farther east than 83%.
  • 🎯1,166 miles east of the geographic center of the Lower 48, near Lebanon, Kansas.
  • 🌏 Dig straight through the Earth from 21204 and you would come out at 39.41°S, 103.37°E — 868 miles from Perth, Australia, the nearest big city to that spot.
  • ☀Longest day of the year: 14h 57m of daylight. Shortest: 9h 23m.
  • 📏 At 6.3 square miles of land, 21204 is bigger than 21% of ZIP codes — room for about 4.8 Central Parks.
🌙 The sky over 21204 today
  • Working out the sun…
🌋 Shake report
  • Checking the USGS…

Source: USGS.

People and housing

Population19,845This ZIP19,845
Households8,747This ZIP8,747
Housing units9,588This ZIP9,588
Median age34.8This ZIP34.8Maryland39.4US 38.9
Median household income$99,606This ZIP$99,606Maryland$103,678US $80,734
Median home value$594,800This ZIP$594,800Maryland$419,900US $332,700
Median gross rent$1,875This ZIP$1,875Maryland$1,705US $1,413
Bachelor's degree or higher73.1%This ZIP73.1%
Mean commute23.8 minThis ZIP23.8 min
Population density3,169.1 / sq miThis ZIP3,169.1 / sq mi

Business and tax activity

Business establishments1,419This ZIP1,419
Employees25,411This ZIP25,411
Annual payroll$1,747,044,000This ZIP$1,747,044,000
Tax returns filed8,970This ZIP8,970
Total adjusted gross income$1,696,252,000This ZIP$1,696,252,000

Land area

Land area6.26 sq miThis ZIP6.26 sq mi
Water area0.10 sq miThis ZIP0.10 sq mi

Other place names in 21204

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

ZIP codes near 21204

ZIPCityDistance
21252 Towson, MD 1.2 mi
21139 Riderwood, MD 1.2 mi
21284 Towson, MD 1.3 mi
21285 Towson, MD 1.4 mi
21093 Lutherville Timonium, MD 2.3 mi
21022 Brooklandville, MD 2.5 mi
21212 Baltimore, MD 2.8 mi
21286 Towson, MD 2.8 mi
21094 Lutherville Timonium, MD 2.9 mi
21209 Baltimore, MD 2.9 mi

Find every ZIP code within 10 miles of 21204 →

Questions about this ZIP code

Where is ZIP code 21204?

21204 is in Towson, Maryland, in Baltimore County, part of the Baltimore-Columbia-Towson, MD metropolitan area. Its published point location is 39.4064, -76.6261.

What county is 21204 in?

21204 lies in Baltimore County.

What area code is 21204?

Towson uses area codes 410, 443 and 667, from NANPA's telephone records.

What time zone is 21204 in?

21204 uses America/New_York.

How many people live in 21204?

About 19,845 people live in ZIP code 21204, in 8,747 households, at 3,169.1 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 21204?

$99,606 a year, against $103,678 across Maryland.

What ZIP codes are near 21204?

The closest are 21252 (1.2 mi), 21139 (1.2 mi), 21284 (1.3 mi), 21285 (1.4 mi) and 21093 (2.3 mi).

Is 21204 a PO Box ZIP code?

21204 is a standard ZIP code. A normal ZIP code with street delivery.

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Cite this page

zipcodes.pro. “21204 ZIP Code — Towson, Maryland (Baltimore County).” Data release 2026-10-12. Retrieved 2026-10-20. https://zipcodes.pro/zip/21204

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