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/94540

94540

ZIP 94540 is in Hayward, California, in Alameda County; area codes 510 and 341; Pacific time. Hayward has 7 ZIP codes in all.

Type
No street area
Time zone
America/Los_Angeles
County
Alameda
Coordinates
37.6802, -121.9215

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 94588, whose figures describe that area — not this ZIP code.

☼ Live from 94540 — Hayward, CA

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Where 94540 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 94540
  • 🔢 Type 94540 into a pocket calculator and turn it upside down: OhShG — not quite a word, sorry.
  • ➕ As a number, 94,540 = 2 × 2 × 5 × 29 × 163. Its digits add up to 22, a total 2,607 other ZIP codes share.
  • 💾In binary, the way a computer stores it: 10111000101001100
  • 🏠 Its numerical neighbours: 94539 (Fremont, CA, 11 mi away) and 94541 (Hayward, CA, 9 mi away).
  • 🔄 Backwards, 94540 becomes 04549 — and that is a real ZIP code: Isle Of Springs, ME, 2,727 miles away.
  • 👥 26 other ZIP codes are made of exactly the same digits (04459, 04495, 04549, 04945, 04954, 05449, …). The farthest-flung twin is 04495 in Winn, ME, 2,769 miles away.
  • 🧭 Farther south than 60% of all ZIP codes, and farther west than 95%.
  • 🎯1,263 miles west of the geographic center of the Lower 48, near Lebanon, Kansas.
  • 🌏 Dig straight through the Earth from 94540 and you would come out at 37.68°S, 58.08°E — 1,007 miles from Port-aux-Français, French Southern Territories, the nearest big city to that spot.
  • ☀Longest day of the year: 14h 46m of daylight. Shortest: 9h 33m.
🌙 The sky over 94540 today
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🌋 Shake report
  • Checking the USGS…

Source: USGS.

Business and tax activity

Business establishments9This ZIP9
Employees90This ZIP90
Annual payroll$7,147,000This ZIP$7,147,000

Land area

ZIP codes near 94540

ZIPCityDistance
94537 Fremont, CA 0.0 mi
94557 Hayward, CA 0.0 mi
94568 Dublin, CA 2.7 mi
94566 Pleasanton, CA 4.6 mi
94552 Castro Valley, CA 5.0 mi
94582 San Ramon, CA 5.9 mi
94542 Hayward, CA 6.0 mi
94570 Moraga, CA 7.0 mi
94583 San Ramon, CA 7.3 mi
94544 Hayward, CA 8.1 mi

Find every ZIP code within 10 miles of 94540 →

Questions about this ZIP code

Where is ZIP code 94540?

94540 is in Hayward, California, in Alameda County, part of the San Francisco-Oakland-Fremont, CA metropolitan area. Its published point location is 37.6802, -121.9215.

What county is 94540 in?

94540 lies in Alameda County.

What area code is 94540?

Hayward uses area codes 510 and 341, from NANPA's telephone records.

What time zone is 94540 in?

94540 uses America/Los_Angeles.

What ZIP codes are near 94540?

The closest are 94537 (0 mi), 94557 (0 mi), 94568 (2.7 mi), 94566 (4.6 mi) and 94552 (5 mi).

Is 94540 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. “94540 ZIP Code — Hayward, California (Alameda County).” Data release 2026-10-12. Retrieved 2026-10-20. https://zipcodes.pro/zip/94540

Machine-readable version of these facts:

curl https://zipcodes.pro/zip/94540.json

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