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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/45123

45123

ZIP 45123 is Greenfield, Ohio, mostly in Highland County; area code 937; Eastern time.

Type
Standard
Time zone
America/New_York
County
Highland +2 more
Metro area
none
Population
8,740
Coordinates
39.3488, -83.3888
☼ Live from 45123 — Greenfield, OH

Weather right now

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Local time: —

Where 45123 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 45123
  • 🔢 Type 45123 into a pocket calculator and turn it upside down: EZISh — not quite a word, sorry.
  • ➕ As a number, 45,123 = 3 × 13 × 13 × 89. Its digits add up to 15, a total 1,657 other ZIP codes share.
  • 💾In binary, the way a computer stores it: 1011000001000011
  • 🏠 Its numerical neighbours: 45122 (Goshen, OH, 41 mi away) and 45130 (Hamersville, OH, 45 mi away).
  • 🔄 Backwards, 45123 becomes 32154, which is not a ZIP code at all.
  • 👥 66 other ZIP codes are made of exactly the same digits (12345, 12435, 12453, 12534, 12543, 13425, …). The farthest-flung twin is 34251 in Myakka City, FL, 830 miles away.
  • 🧭 Farther north than 51% of all ZIP codes, and farther east than 62%.
  • 🎯809 miles east of the geographic center of the Lower 48, near Lebanon, Kansas.
  • 🌏 Dig straight through the Earth from 45123 and you would come out at 39.35°S, 96.61°E — 1,192 miles from Perth, Australia, the nearest big city to that spot.
  • ☀Longest day of the year: 14h 57m of daylight. Shortest: 9h 23m.
  • 📏 At 106.8 square miles of land, 45123 is bigger than 79% of ZIP codes — room for about 81 Central Parks.
🌙 The sky over 45123 today
  • Working out the sun…
🌋 Shake report
  • Checking the USGS…

Source: USGS.

People and housing

Population8,740This ZIP8,740
Households3,313This ZIP3,313
Housing units3,806This ZIP3,806
Median age36.8This ZIP36.8Ohio39.7US 38.9
Median household income$62,404This ZIP$62,404Ohio$71,389US $80,734
Median home value$161,700This ZIP$161,700Ohio$214,800US $332,700
Median gross rent$756This ZIP$756Ohio$1,034US $1,413
Bachelor's degree or higher13.8%This ZIP13.8%
Mean commute25.1 minThis ZIP25.1 min
Population density81.9 / sq miThis ZIP81.9 / sq mi

Business and tax activity

Business establishments134This ZIP134
Employees1,773This ZIP1,773
Annual payroll$76,858,000This ZIP$76,858,000
Tax returns filed3,650This ZIP3,650
Total adjusted gross income$192,422,000This ZIP$192,422,000

Land area

Land area106.76 sq miThis ZIP106.76 sq mi
Water area1.21 sq miThis ZIP1.21 sq mi

Counties 45123 spans

A ZIP code is a mail route and ignores county lines. Shares are by overlapping land area.

CountyShare of this ZIP
Highland County 42.7%
Ross County 33.2%
Fayette County 24.1%

Other place names in 45123

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

ZIP codes near 45123

ZIPCityDistance
45681 South Salem, OH 7.8 mi
45135 Leesburg, OH 8.2 mi
45628 Frankfort, OH 10.8 mi
45132 Highland, OH 11.3 mi
45612 Bainbridge, OH 11.4 mi
45624 Cynthiana, OH 12.3 mi
43160 Washington Court House, OH 12.7 mi
45617 Bourneville, OH 13.4 mi
43115 Clarksburg, OH 15.2 mi
45159 New Vienna, OH 16.2 mi

Find every ZIP code within 10 miles of 45123 →

Questions about this ZIP code

Where is ZIP code 45123?

45123 is in Greenfield, Ohio, in Highland County. Its published point location is 39.3488, -83.3888.

What county is 45123 in?

45123 spans 3 counties: Highland County, Ross County and Fayette County. Most of it falls in Highland 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 45123?

Greenfield uses area code 937, from NANPA's telephone records.

What time zone is 45123 in?

45123 uses America/New_York.

How many people live in 45123?

About 8,740 people live in ZIP code 45123, in 3,313 households, at 81.9 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 45123?

$62,404 a year, against $71,389 across Ohio.

What ZIP codes are near 45123?

The closest are 45681 (7.8 mi), 45135 (8.2 mi), 45628 (10.8 mi), 45132 (11.3 mi) and 45612 (11.4 mi).

Is 45123 a PO Box ZIP code?

45123 is a standard ZIP code. A normal ZIP code with street delivery.

Download or cite

Cite this page

zipcodes.pro. “45123 ZIP Code — Greenfield, Ohio (Highland County).” Data release 2026-10-12. Retrieved 2026-10-20. https://zipcodes.pro/zip/45123

Machine-readable version of these facts:

curl https://zipcodes.pro/zip/45123.json

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