40121 ZIP Code — Fort Knox, KY
Hardin County, Kentucky
ZIP code 40121 is located in Fort Knox, Kentucky, within Hardin County. It covers approximately 35.22 square miles and serves a population of 8,655 residents. This is a standard ZIP code in the Eastern (ET) timezone, served by area code 502.
About ZIP code 40121
The housing stock consists of a mix of housing types. Much of the housing stock is relatively new, reflecting recent development activity.
Median household income is $76,864. The poverty rate of 4% is below the national average.
The dominant occupation class is management, business, and professional, with education and healthcare as the leading industry. The average commute of 12 minutes is near the national average.
Educational attainment is near the national average, with 41% of residents holding a bachelor's degree or higher.
Notable community characteristics include a notable veteran presence at 23% of civilians, above the national average of 7%.
8,655
population
35.22
sq mi land
Standard
ZIP type
Eastern (ET)
timezone
40121 ZIP code map
Cities in ZIP code 40121
Below are the cities the US Postal Service accepts for ZIP code 40121. Using any city not on this list may result in mail delivery delays.
| City | Status |
|---|---|
| Fort Knox | Preferred |
Nearby ZIP codes
40122 Fort Knox (2 mi)
40160 Radcliff (3.6 mi)
40177 West Point (4.6 mi)
40155 Muldraugh (7.6 mi)
40175 Vine Grove (9.2 mi)
40162 Rineyville (10.2 mi)
40117 Ekron (10.9 mi)
40150 Lebanon Junction (11.3 mi)
42701 Elizabethtown (13 mi)
40165 Shepherdsville (13.4 mi)
40272 Louisville (14.2 mi)
40108 Brandenburg (14.7 mi)
Demographics
updated 05/2026
| Population | |
|---|---|
| Total population | 8,655 |
| Population density | 246 / sq mi |
| State FIPS | 21 |
| County FIPS | 093 |
| Geography | |
|---|---|
| Land area | 35.22 sq mi |
| Water area | 0.08 sq mi |
| Latitude | 37.8700 |
| Longitude | -85.9326 |
| Timezone | Eastern (ET) |
| Area code | 502 |
Total population by age
Gender
Race & ethnicity
Economics
updated 05/2026
Household income
| Income range | This ZIP | County avg | State avg |
|---|---|---|---|
| Under $50k | 37.0% | 44.3% | 47.9% |
| $50k – $100k | 35.1% | 32.6% | 30.3% |
| $100k – $200k | 24.9% | 19.6% | 17.6% |
| Over $200k | 3.0% | 3.5% | 4.2% |
Demographics & statistics
8,655
Population
246
People per sq mi
24.7
Median age
$76,864
Median household income
$31,450
Per capita income
$0
Median home value
$1,178
Median monthly rent
0.7%
Home ownership
4.3%
Poverty rate
8.8%
Unemployment
266
Housing units
40.7%
Bachelor's or higher
Age distribution
Male
Female
547
Under 5
440
456
5–9
368
358
10–14
288
321
15–19
259
740
20–24
595
1,048
25–34
843
884
35–44
712
292
45–54
236
37
55–59
29
43
60–64
34
44
65–74
36
23
75–84
18
2
85+
2
← Male
Female →
Age summary
| Group | Count | % |
|---|---|---|
| Under 18 | 2,690 | 31.1% |
| 18 and over | 5,965 | 68.9% |
| 65 and over | 125 | 1.4% |
| Median age | 24.7 years | |
Race & ethnicity
White
51.2%
Black or African American
16.3%
Hispanic or Latino
12.2%
Two or more races
12.1%
Other race
3.2%
Asian
2.5%
Native Hawaiian / Pacific Islander
1.8%
American Indian / Alaska Native
0.8%
| Group | Count | % |
|---|---|---|
| White | 5,045 | 51.2% |
| Black or African American | 1,612 | 16.3% |
| Hispanic or Latino | 1,208 | 12.2% |
| Two or more races | 1,191 | 12.1% |
| Other race | 315 | 3.2% |
| Asian | 244 | 2.5% |
| Native Hawaiian / Pacific Islander | 173 | 1.8% |
| American Indian / Alaska Native | 75 | 0.8% |
Household income
| Income range | This ZIP | County avg | State avg |
|---|---|---|---|
| Under $50k | 37.0% | 44.3% | 47.9% |
| $50k – $100k | 35.1% | 32.6% | 30.3% |
| $100k – $200k | 24.9% | 19.6% | 17.6% |
| Over $200k | 3.0% | 3.5% | 4.2% |
Under $10k
1.4%
$10k–$15k
1.0%
$15k–$25k
2.4%
$25k–$35k
7.3%
$35k–$50k
10.2%
$50k–$75k
25.9%
$75k–$100k
11.0%
$100k–$150k
27.1%
$150k–$200k
9.4%
$200k+
4.4%
| Range | % of households |
|---|---|
| Under $10k | 1.4% |
| $10k–$15k | 1.0% |
| $15k–$25k | 2.4% |
| $25k–$35k | 7.3% |
| $35k–$50k | 10.2% |
| $50k–$75k | 25.9% |
| $75k–$100k | 11.0% |
| $100k–$150k | 27.1% |
| $150k–$200k | 9.4% |
| $200k+ | 4.4% |
| Median income | $76,864 |
Housing
Home values
Under $50k
100.0%
Housing overview
| Metric | Value |
|---|---|
| Median home value | $0 |
| Median rent / month | $1,178 |
| Owner occupied | 0.7% |
| Renter occupied | 99.3% |
| Vacant | 9.9% |
| Single-family detached | 21.9% |
| Large apartment buildings | 7.8% |
| Mobile homes | 0.2% |
| Median rooms | 5.5 |
| Avg household size (owned) | 2.27 |
Year built
| Era | % |
|---|---|
| 2020 or later | 0.0% |
| 2010–2019 | 19.7% |
| 2000–2009 | 11.1% |
| 1990–1999 | 4.4% |
| 1980–1989 | 9.9% |
| 1970–1979 | 12.1% |
| 1960–1969 | 17.5% |
| 1950–1959 | 13.9% |
| 1940–1949 | 5.4% |
| 1939 or earlier | 6.1% |
Bedrooms
| Size | % of units |
|---|---|
| No bedroom (studio) | 9.8% |
| 1 bedroom | 3.3% |
| 2 bedrooms | 10.4% |
| 3 bedrooms | 58.2% |
| 4 bedrooms | 12.8% |
| 5+ bedrooms | 5.5% |
Vehicles per household
| Vehicles | % of households |
|---|---|
| No vehicle | 1.8% |
| 1 vehicle | 35.0% |
| 2 vehicles | 53.6% |
| 3 or more | 9.7% |
Heating fuel
| Fuel type | % |
|---|---|
| Utility gas | 39.9% |
| Electricity | 58.7% |
| Propane / LP gas | 0.3% |
| Wood | 0.3% |
| No fuel used | 0.5% |
Households & families
| Household type | Count | % |
|---|---|---|
| Married-couple family | 1,411 | 61.7% |
| Cohabiting couple | 79 | 3.5% |
| Male householder, no spouse | 478 | 20.9% |
| Female householder, no spouse | 320 | 14.0% |
| Households with children under 18 | 1,190 | 52.0% |
| Households with seniors (65+) | 89 | 3.9% |
| Average household size | 3.10 | |
Marital status
| Status | Male | Female |
|---|---|---|
| Never married | 47.7% | 26.2% |
| Married | 44.7% | 65.6% |
| Separated | 0.6% | 0.1% |
| Widowed | 0.0% | 2.0% |
| Divorced | 7.1% | 6.1% |
Education
Less than 9th grade
1.7%
Some HS, no diploma
3.5%
HS graduate
14.3%
Some college, no degree
27.8%
Associate's degree
12.1%
Bachelor's degree
21.5%
Graduate / professional
19.2%
| Metric | % |
|---|---|
| HS diploma or higher | 94.8% |
| Bachelor's or higher | 40.7% |
School enrollment (ages 3–17)
| Type | Count | % |
|---|---|---|
| Nursery / preschool | 466 | 16.0% |
| Kindergarten | 113 | 3.9% |
| Elementary school | 1,258 | 43.1% |
| High school | 343 | 11.8% |
| College / grad school | 739 | 25.3% |
Employment
Industry of employment
Education & healthcare
24.8%
Retail trade
19.0%
Public administration
18.2%
Arts, food & hospitality
8.9%
Manufacturing
8.3%
Professional & management
6.0%
Construction
4.1%
Agriculture & mining
2.7%
Transportation & utilities
2.7%
Information
2.5%
Finance & real estate
1.2%
Other services
1.2%
Wholesale trade
0.4%
Occupation
| Category | % |
|---|---|
| Management, business & arts | 37.6% |
| Service | 17.9% |
| Sales & office | 23.0% |
| Natural resources & construction | 9.4% |
| Production & transportation | 12.1% |
Employment type
| Type | % |
|---|---|
| Private sector | 60.0% |
| Government | 39.4% |
| Self-employed | 0.6% |
| Unpaid family workers | 0.0% |
Commute
| Method | % |
|---|---|
| Drive alone | 70.8% |
| Carpool | 7.9% |
| Public transit | 0.8% |
| Walk | 17.1% |
| Work from home | 2.5% |
| Other means | 1.0% |
| Avg commute (minutes) | 11.9 |
Poverty
All people
4.3%
Under 18 years
7.0%
18 and over
2.6%
Married-couple families
2.1%
Female-led households
16.9%
Income support
| Source | % of households |
|---|---|
| Social Security | 7.2% |
| Retirement income | 13.3% |
| Supplemental Security | 2.8% |
| Cash public assistance | 0.7% |
| Food stamps / SNAP | 2.0% |
Health indicators
| Condition | % |
|---|---|
| Obesity | 34.6% |
| High blood pressure | 19.3% |
| High cholesterol | 17.3% |
| Diabetes | 3.4% |
| Heart disease | 1.5% |
| Stroke | 0.9% |
| Asthma | 10.6% |
| Arthritis | 10.4% |
| Kidney disease | 1.0% |
| Pulmonary disease | 3.1% |
| Cancer | 1.6% |
| Behavior / access | % |
|---|---|
| Smoking | 17.9% |
| Binge drinking | 22.3% |
| No physical activity | 21.0% |
| Less than 7 hrs sleep | 38.0% |
| Depression | 24.3% |
| Fair or poor health | 10.6% |
| Poor mental health | 19.6% |
| Poor physical health | 7.0% |
| No health insurance | 11.5% |
| Visited doctor (checkup) | 69.4% |
| Visited dentist | 56.7% |
| Cholesterol screening | 82.1% |
| Teeth loss | 10.4% |
Veterans & disability
| Veterans | Count | % |
|---|---|---|
| Civilian veterans | 667 | 23.3% |
| Disability | % |
|---|---|
| Any disability | 9.7% |
| Under 18 | 6.2% |
| 18–64 years | 12.2% |
| 65 and over | 33.6% |
Health insurance coverage
| Type | % |
|---|---|
| Private insurance | 86.8% |
| Public insurance | 16.8% |
| No insurance | 7.3% |
| Uninsured under 19 | 5.0% |
Language & origin
Language spoken at home (age 5+)
| Language | Count | % |
|---|---|---|
| English only | 7,668 | 88.6% |
| Spanish | 207 | 2.7% |
| Other Indo-European | 170 | 2.2% |
| Asian & Pacific Islander | 14 | 0.2% |
| Other languages | 23 | 0.3% |
Place of birth & citizenship
| Origin | Count | % |
|---|---|---|
| Native born (US) | 8,101 | 93.6% |
| Born in same state | 7,561 | 87.4% |
| Born in different state | 1,174 | 13.6% |
| Foreign born | 540 | 6.2% |
| Naturalized citizen | 554 | 6.4% |
| Not a US citizen | 311 | 56.1% |
Ancestry
| Ancestry | Count | % |
|---|---|---|
| French | 1,048 | 12.1% |
| Italian | 747 | 8.6% |
| Arab | 500 | 5.8% |
| Polish | 474 | 5.5% |
| Ancestry | Count | % |
|---|---|---|
| English | 60 | 0.7% |
| Dutch | 22 | 0.3% |
| German | 5 | 0.1% |
| Irish | 4 | 0% |
Technology access
| Metric | % of households |
|---|---|
| Computer access | 26.4% |
| Internet access | 98.5% |
Source: U.S. Census Bureau, American Community Survey 2025 estimates.
Frequently asked questions about ZIP code 40121
What city is ZIP code 40121 in?
ZIP code 40121 is primarily assigned to Fort Knox, Kentucky.
What county is ZIP code 40121 in?
ZIP code 40121 falls within Hardin County, Kentucky.
Is ZIP code 40121 family-oriented?
31% of residents in ZIP code 40121 are under 18, reflecting a younger, family-oriented community.
Does ZIP code 40121 have a large veteran population?
23% of civilians in ZIP code 40121 are veterans, above the national average of ~7%.
What is the population of ZIP code 40121?
ZIP code 40121 has an estimated population of 8,655 residents, with a density of 246 people per square mile.
What is the median household income in ZIP code 40121?
The median household income in ZIP code 40121 is $76,864, above the national median of ~$75,000.
What timezone is ZIP code 40121 in?
ZIP code 40121 observes the EST timezone.