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zipcodes.pro — ZIP/40121

40121

ZIP 40121 is in Fort Knox, Kentucky, mostly in Hardin County; Eastern time. Fort Knox has 2 ZIP codes; the other is 40122.

Type
Standard
Time zone
America/New_York
County
Hardin +1 more
Metro area
Elizabethtown, KY
Population
8,836
Coordinates
37.9269, -85.9598
☼ Live from 40121 — Fort Knox, KY

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Local time: —

Where 40121 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 40121
  • 🔢 Type 40121 into a pocket calculator and turn it upside down: IZIOh — not quite a word, sorry.
  • ➕ As a number, 40,121 = 53 × 757. Its digits add up to 8, a total 251 other ZIP codes share.
  • 💾In binary, the way a computer stores it: 1001110010111001
  • 🏠 Its numerical neighbours: 40119 (Falls Of Rough, KY, 39 mi away) and 40122 (Fort Knox, KY, 2 mi away).
  • 🔄 Backwards, 40121 becomes 12104, which is not a ZIP code at all.
  • 👥 34 other ZIP codes are made of exactly the same digits (02114, 02141, 04112, 04211, 10124, 11024, …). The farthest-flung twin is 04211 in Auburn, ME, 924 miles away.
  • 🧭 Farther south than 59% of all ZIP codes, and farther east than 54%.
  • 🎯691 miles east of the geographic center of the Lower 48, near Lebanon, Kansas.
  • 🌏 Dig straight through the Earth from 40121 and you would come out at 37.93°S, 94.04°E — 1,299 miles from Perth, Australia, the nearest big city to that spot.
  • ☀Longest day of the year: 14h 48m of daylight. Shortest: 9h 32m.
  • 📏 At 35.2 square miles of land, 40121 is bigger than 50% of ZIP codes — room for about 27 Central Parks.
🌙 The sky over 40121 today
  • Working out the sun…
🌋 Shake report
  • Checking the USGS…

Source: USGS.

People and housing

Population8,836This ZIP8,836
Households2,226This ZIP2,226
Housing units2,497This ZIP2,497
Median age24.0This ZIP24.0Kentucky39.1US 38.9
Median household income$82,663This ZIP$82,663Kentucky$63,726US $80,734
Median gross rent$1,502This ZIP$1,502Kentucky$967US $1,413
Bachelor's degree or higher48.3%This ZIP48.3%
Mean commute12.4 minThis ZIP12.4 min
Population density250.9 / sq miThis ZIP250.9 / sq mi

Business and tax activity

Business establishments55This ZIP55
Employees1,015This ZIP1,015
Annual payroll$55,488,000This ZIP$55,488,000
Tax returns filed2,480This ZIP2,480
Total adjusted gross income$167,562,000This ZIP$167,562,000

Land area

Land area35.22 sq miThis ZIP35.22 sq mi
Water area0.08 sq miThis ZIP0.08 sq mi

Counties 40121 spans

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

CountyShare of this ZIP
Hardin County 84.1%
Meade County 15.9%

Other place names in 40121

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

ZIP codes near 40121

ZIPCityDistance
40155 Muldraugh, KY 2.4 mi
40122 Fort Knox, KY 2.5 mi
40177 West Point, KY 5.6 mi
40160 Radcliff, KY 8.0 mi
40117 Ekron, KY 9.2 mi
40175 Vine Grove, KY 10.3 mi
47135 Laconia, IN 10.5 mi
40272 Louisville, KY 12.0 mi
40108 Brandenburg, KY 12.0 mi
47117 Elizabeth, IN 12.4 mi

Find every ZIP code within 10 miles of 40121 →

Questions about this ZIP code

Where is ZIP code 40121?

40121 is in Fort Knox, Kentucky, in Hardin County, part of the Elizabethtown, KY metropolitan area. Its published point location is 37.9269, -85.9598.

What county is 40121 in?

40121 spans 2 counties: Hardin County and Meade County. Most of it falls in Hardin 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 time zone is 40121 in?

40121 uses America/New_York.

How many people live in 40121?

About 8,836 people live in ZIP code 40121, in 2,226 households, at 250.9 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 40121?

$82,663 a year, against $63,726 across Kentucky.

What ZIP codes are near 40121?

The closest are 40155 (2.4 mi), 40122 (2.5 mi), 40177 (5.6 mi), 40160 (8 mi) and 40117 (9.2 mi).

Is 40121 a PO Box ZIP code?

40121 is a standard ZIP code. A normal ZIP code with street delivery.

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Cite this page

zipcodes.pro. “40121 ZIP Code — Fort Knox, Kentucky (Hardin County).” Data release 2026-10-12. Retrieved 2026-10-20. https://zipcodes.pro/zip/40121

Machine-readable version of these facts:

curl https://zipcodes.pro/zip/40121.json

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