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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/02451

02451

ZIP 02451 is in Waltham, Massachusetts, in Middlesex County; area codes 781, 617 and 339; Eastern time. Waltham has 4 ZIP codes; the others are 02452, 02453 and 02454.

Type
Standard
Time zone
America/New_York
County
Middlesex
Population
17,393
Coordinates
42.4015, -71.2530
☼ Live from 02451 — Waltham, MA

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Where 02451 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 02451
  • 🔢 Type 02451 into a pocket calculator and turn it upside down: IShZO — not quite a word, sorry.
  • ➕ As a number, 2,451 = 3 × 19 × 43. Its digits add up to 12, a total 940 other ZIP codes share.
  • 💾In binary, the way a computer stores it: 100110010011
  • 🏠 Its numerical neighbours: 02447 (Brookline Village, MA, 8 mi away) and 02452 (Waltham, MA, 2 mi away).
  • 🔄 Backwards, 02451 becomes 15420 — and that is a real ZIP code: Cardale, PA, 478 miles away.
  • 👥 73 other ZIP codes are made of exactly the same digits (01245, 01254, 01452, 01524, 01542, 02145, …). The farthest-flung twin is 51240 in Inwood, IA, 1,273 miles away.
  • 🧭 Farther north than 78% of all ZIP codes, and farther east than 96%.
  • 🎯1,427 miles east of the geographic center of the Lower 48, near Lebanon, Kansas.
  • 🌏 Dig straight through the Earth from 02451 and you would come out at 42.40°S, 108.75°E — 821 miles from Perth, Australia, the nearest big city to that spot.
  • ☀Longest day of the year: 15h 17m of daylight. Shortest: 9h 04m.
  • 📏 At 5.3 square miles of land, 02451 is bigger than 19% of ZIP codes — room for about 4.0 Central Parks.
🌙 The sky over 02451 today
  • Working out the sun…
🌋 Shake report
  • Checking the USGS…

Source: USGS.

People and housing

Population17,393This ZIP17,393
Households7,481This ZIP7,481
Housing units7,748This ZIP7,748
Median age40.3This ZIP40.3Massachusetts40.0US 38.9
Median household income$122,335This ZIP$122,335Massachusetts$103,960US $80,734
Median home value$753,000This ZIP$753,000Massachusetts$562,100US $332,700
Median gross rent$2,677This ZIP$2,677Massachusetts$1,762US $1,413
Bachelor's degree or higher56.0%This ZIP56.0%
Mean commute26.1 minThis ZIP26.1 min
Population density3,268.7 / sq miThis ZIP3,268.7 / sq mi

Business and tax activity

Business establishments1,195This ZIP1,195
Employees59,760This ZIP59,760
Annual payroll$8,176,869,000This ZIP$8,176,869,000
Tax returns filed9,660This ZIP9,660
Total adjusted gross income$1,076,096,000This ZIP$1,076,096,000

Land area

Land area5.32 sq miThis ZIP5.32 sq mi
Water area0.71 sq miThis ZIP0.71 sq mi

Other place names in 02451

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

ZIP codes near 02451

ZIPCityDistance
02452 Waltham, MA 1.7 mi
02453 Waltham, MA 2.3 mi
02421 Lexington, MA 2.6 mi
02454 Waltham, MA 3.1 mi
01773 Lincoln, MA 3.4 mi
02455 North Waltham, MA 3.6 mi
02479 Waverley, MA 3.7 mi
02495 Nonantum, MA 3.7 mi
02478 Belmont, MA 3.7 mi
02465 West Newton, MA 3.8 mi

Find every ZIP code within 10 miles of 02451 →

Questions about this ZIP code

Where is ZIP code 02451?

02451 is in Waltham, Massachusetts, in Middlesex County, part of the Boston-Cambridge-Newton, MA-NH metropolitan area. Its published point location is 42.4015, -71.2530.

What county is 02451 in?

02451 lies in Middlesex County.

What area code is 02451?

Waltham uses area codes 781, 617 and 339, from NANPA's telephone records.

What time zone is 02451 in?

02451 uses America/New_York.

How many people live in 02451?

About 17,393 people live in ZIP code 02451, in 7,481 households, at 3,268.7 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 02451?

$122,335 a year, against $103,960 across Massachusetts.

What ZIP codes are near 02451?

The closest are 02452 (1.7 mi), 02453 (2.3 mi), 02421 (2.6 mi), 02454 (3.1 mi) and 01773 (3.4 mi).

Is 02451 a PO Box ZIP code?

02451 is a standard ZIP code. A normal ZIP code with street delivery.

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Cite this page

zipcodes.pro. “02451 ZIP Code — Waltham, Massachusetts (Middlesex County).” Data release 2026-10-12. Retrieved 2026-10-20. https://zipcodes.pro/zip/02451

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