08540
ZIP 08540 is in Princeton, New Jersey, mostly in Mercer County; area codes 609 and 640; Eastern time. Princeton has 5 ZIP codes; the others are 08541, 08542, 08543 and 08544.
- Type
- Standard
- Time zone
- America/New_York
- County
- Mercer +2 more
- Metro area
- Trenton-Princeton, NJ
- Population
- 50,388
- Coordinates
- 40.3647, -74.6563
Weather right now
Asking the National Weather Service…
Where 08540 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.
- 🔢 Type 08540 into a pocket calculator and turn it upside down: OhSBO — not quite a word, sorry.
- ➕ As a number, 8,540 = 2 × 2 × 5 × 7 × 61. Its digits add up to 17, a total 2,133 other ZIP codes share.
- 💾In binary, the way a computer stores it:
10000101011100 - 🏠 Its numerical neighbours: 08536 (Plainsboro, NJ, 4 mi away) and 08541 (Princeton, NJ, 1 mi away).
- 🔄 Backwards, 08540 becomes 04580, which is not a ZIP code at all.
- 👥 27 other ZIP codes are made of exactly the same digits (04085, 04850, 05048, 05084, 05408, 05840, …). The farthest-flung twin is 85004 in Phoenix, AZ, 2,105 miles away.
- 🧭 Farther north than 60% of all ZIP codes, and farther east than 88%.
- 🎯1,261 miles east of the geographic center of the Lower 48, near Lebanon, Kansas.
- 🌏 Dig straight through the Earth from 08540 and you would come out at 40.36°S, 105.34°E — 825 miles from Perth, Australia, the nearest big city to that spot.
- ☀Longest day of the year: 15h 03m of daylight. Shortest: 9h 17m.
- 📏 At 51.7 square miles of land, 08540 is bigger than 60% of ZIP codes — room for about 39 Central Parks.
- Working out the sun…
- Checking the USGS…
Source: USGS.
People and housing
| Population | 50,388This ZIP50,388 |
|---|---|
| Households | 18,609This ZIP18,609 |
| Housing units | 19,622This ZIP19,622 |
| Median age | 40.6This ZIP40.6New Jersey40.1US 38.9 |
| Median household income | $176,983This ZIP$176,983New Jersey$103,556US $80,734 |
| Median home value | $767,900This ZIP$767,900New Jersey$454,400US $332,700 |
| Median gross rent | $2,218This ZIP$2,218New Jersey$1,720US $1,413 |
| Bachelor's degree or higher | 82.7%This ZIP82.7% |
| Mean commute | 28.5 minThis ZIP28.5 min |
| Population density | 974.3 / sq miThis ZIP974.3 / sq mi |
Business and tax activity
| Business establishments | 2,180This ZIP2,180 |
|---|---|
| Employees | 48,656This ZIP48,656 |
| Annual payroll | $6,074,201,000This ZIP$6,074,201,000 |
| Tax returns filed | 22,230This ZIP22,230 |
| Total adjusted gross income | $6,039,911,000This ZIP$6,039,911,000 |
Land area
| Land area | 51.72 sq miThis ZIP51.72 sq mi |
|---|---|
| Water area | 1.03 sq miThis ZIP1.03 sq mi |
Counties 08540 spans
A ZIP code is a mail route and ignores county lines. Shares are by overlapping land area.
| County | Share of this ZIP |
|---|---|
| Mercer County | 62.6% |
| Somerset County | 26.5% |
| Middlesex County | 10.9% |
Other place names in 08540
Census places whose land this ZIP code overlaps. The Postal Service may accept other city names in an address, too.
- Princeton
- East Rocky Hill
- Griggstown
- Ten Mile Run
- Heathcote
- Kingston
- Princeton Junction
- Kendall Park
- Monmouth Junction
ZIP codes near 08540
| ZIP | City | Distance |
|---|---|---|
08542 | Princeton, NJ | 0.7 mi |
08541 | Princeton, NJ | 1.1 mi |
08544 | Princeton, NJ | 1.3 mi |
08528 | Kingston, NJ | 2.5 mi |
08553 | Rocky Hill, NJ | 2.6 mi |
08504 | Blawenburg, NJ | 3.8 mi |
08558 | Skillman, NJ | 4.2 mi |
08536 | Plainsboro, NJ | 4.3 mi |
08502 | Belle Mead, NJ | 5.8 mi |
08550 | Princeton Junction, NJ | 6.1 mi |
Find every ZIP code within 10 miles of 08540 →
Questions about this ZIP code
Where is ZIP code 08540?
08540 is in Princeton, New Jersey, in Mercer County, part of the Trenton-Princeton, NJ metropolitan area. Its published point location is 40.3647, -74.6563.
What county is 08540 in?
08540 spans 3 counties: Mercer County, Somerset County and Middlesex County. Most of it falls in Mercer County, measured by overlapping land area — the county holding the most land in a ZIP code is not always the one holding the most residents.
What area code is 08540?
Princeton uses area codes 609 and 640, from NANPA's telephone records.
What time zone is 08540 in?
08540 uses America/New_York.
How many people live in 08540?
About 50,388 people live in ZIP code 08540, in 18,609 households, at 974.3 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 08540?
$176,983 a year, against $103,556 across New Jersey.
What ZIP codes are near 08540?
The closest are 08542 (0.7 mi), 08541 (1.1 mi), 08544 (1.3 mi), 08528 (2.5 mi) and 08553 (2.6 mi).
Is 08540 a PO Box ZIP code?
08540 is a standard ZIP code. A normal ZIP code with street delivery.
Download or cite
Cite this page
zipcodes.pro. “08540 ZIP Code — Princeton, New Jersey (Mercer County).” Data release 2026-10-12. Retrieved 2026-10-20. https://zipcodes.pro/zip/08540
Machine-readable version of these facts:
curl https://zipcodes.pro/zip/08540.jsonUnderlying data is public domain or openly licensed — sources, vintages and licences.