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/20604

20604

ZIP 20604 is in Waldorf, Maryland, in Charles County; area codes 240, 301 and 227; Eastern time. Waldorf has 4 ZIP codes; the others are 20601, 20602 and 20603.

Type
No street area
Time zone
America/New_York
County
Charles
Coordinates
38.5095, -76.9817

The Census map gives this ZIP code no delivery area of its own, which usually means it serves post office boxes, a single organization or a post office rather than streets of homes.

This ZIP code has no Census tabulation area of its own. Its point falls inside ZCTA 20646, whose figures describe that area — not this ZIP code.

☼ Live from 20604 — Waldorf, MD

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Local time: —

Where 20604 is

This ZIP code has no Census tabulation area, so there is no boundary to draw — the marker is its published point location.

★ Weird and wonderful facts about 20604
  • 🔢 Type 20604 into a pocket calculator and turn it upside down: hOgOZ — not quite a word, sorry.
  • ➕ As a number, 20,604 = 2 × 2 × 3 × 17 × 101. Its digits add up to 12, a total 940 other ZIP codes share.
  • 💾In binary, the way a computer stores it: 101000001111100
  • 🏠 Its numerical neighbours: 20603 (Waldorf, MD, 8 mi away) and 20606 (Abell, MD, 22 mi away).
  • 🔄 Backwards, 20604 becomes 40602 — and that is a real ZIP code: Frankfort, KY, 428 miles away.
  • 👥 27 other ZIP codes are made of exactly the same digits (00624, 02460, 04062, 04260, 06024, 06042, …). The farthest-flung twin is 00624 in Penuelas, PR, 1,543 miles away.
  • 🧭 Farther south than 55% of all ZIP codes, and farther east than 82%.
  • 🎯1,158 miles east of the geographic center of the Lower 48, near Lebanon, Kansas.
  • 🌏 Dig straight through the Earth from 20604 and you would come out at 38.51°S, 103.02°E — 854 miles from Perth, Australia, the nearest big city to that spot.
  • ☀Longest day of the year: 14h 51m of daylight. Shortest: 9h 28m.
🌙 The sky over 20604 today
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🌋 Shake report
  • Checking the USGS…

Source: USGS.

Business and tax activity

Business establishments16This ZIP16
Employees148This ZIP148
Annual payroll$6,215,000This ZIP$6,215,000

Land area

ZIP codes near 20604

ZIPCityDistance
20646 La Plata, MD 1.3 mi
20677 Port Tobacco, MD 3.1 mi
20611 Bel Alton, MD 3.8 mi
20695 White Plains, MD 5.4 mi
20675 Pomfret, MD 5.4 mi
20632 Faulkner, MD 6.2 mi
20693 Welcome, MD 6.7 mi
20602 Waldorf, MD 6.9 mi
20617 Bryantown, MD 7.4 mi
20603 Waldorf, MD 8.3 mi

Find every ZIP code within 10 miles of 20604 →

Questions about this ZIP code

Where is ZIP code 20604?

20604 is in Waldorf, Maryland, in Charles County, part of the Washington-Arlington-Alexandria, DC-VA-MD-WV metropolitan area. Its published point location is 38.5095, -76.9817.

What county is 20604 in?

20604 lies in Charles County.

What area code is 20604?

Waldorf uses area codes 240, 301 and 227, from NANPA's telephone records.

What time zone is 20604 in?

20604 uses America/New_York.

What ZIP codes are near 20604?

The closest are 20646 (1.3 mi), 20677 (3.1 mi), 20611 (3.8 mi), 20695 (5.4 mi) and 20675 (5.4 mi).

Is 20604 a PO Box ZIP code?

Possibly. The Census map gives this ZIP code no delivery area of its own, which usually means it serves post office boxes, a single organization or a post office rather than streets of homes.

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Cite this page

zipcodes.pro. “20604 ZIP Code — Waldorf, Maryland (Charles County).” Data release 2026-10-12. Retrieved 2026-10-20. https://zipcodes.pro/zip/20604

Machine-readable version of these facts:

curl https://zipcodes.pro/zip/20604.json

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