Fort Knox, KY · standard
ZIP Code 40121
Hardin County, Kentucky - Census ACS demographics, housing tenure, and business patterns, benchmarked against every US ZIP.
- 10,124
- 115/sq mi High-density area
- $82,663
- Median income Near-median income area
- 48.3%
- Bachelor's or higher Above-average bachelor's attainment
National ZIP placement
Fort Knox pairs an above-median household income, in a rural, renter-heavy area.
- Top 35%
- household income, US ZIPs
- 115
- people per sq mi
- 0%
- owner-occupied homes
Source: U.S. Census Bureau ACS 5-Year Estimates (2019–2023). Percentiles rank ZIP 40121 against every reporting US ZIP.
ZIP code 40121 is a mid-sized community (a standard USPS delivery area) in Fort Knox, Hardin County, Kentucky, home to 10,124 residents across 87.7 square miles, a density of 115 people per square mile, in the New York time zone.
ZIP 40121 lands in the middle-income range, with a median household income of $82,663 (39% above the average Kentucky ZIP), while per-capita income is $32,370. The poverty rate is 9.0%, with unemployment at 5.3%; those measures add context to the income figure. The ACS does not report a median home value for this ZIP, so housing cost context is limited to the available tenure and rent fields.
A solid share of residents have a four-year degree: 48.3% of adults hold a bachelor's degree or higher, the median age is 24, and the average commute is 12 minutes. The page also surfaces 5 ZIP codes within roughly 10 miles and 6 more in Hardin County, so 40121 can be compared with both its immediate and county-level context.
Every figure on this page is sourced from the U.S. Census Bureau American Community Survey 5-Year Estimates (including median rent) and the FHFA House Price Index, no estimates, no proprietary scoring. Verify with Census →
Top industries in ZIP 40121
Top 5 sectors by establishment count in Fort Knox, KY
Which industries have the most business establishments in ZIP 40121.
- Professional, scientific, and technical services
Professional, scientific, and technical services
14 establishments
- Administrative and support and waste management and remediation services
Administrative and support and waste management and remediation services
9 establishments
- Accommodation and food services
Accommodation and food services
6 establishments
- Other services (except public administration)
Other services (except public administration)
6 establishments
- Retail trade 5
Retail trade
5 establishments
What this shows Establishment counts come from the Census ZIP Code Business Patterns program, which counts physical business locations rather than employees or revenue.
Source: U.S. Census Bureau, American Community Survey 5-Year Estimates + ZIP Code Business Patterns + FHFA HPI ACS demographics and median rent, ZBP business establishments, FHFA HPI for ZIP 40121, Fort Knox, KY · 2023 Census ACS 5-Year Estimates use a rolling 60-month sample for stable small-geography estimates; ZBP updated annually; FHFA HPI updated quarterly/annually.
Quick Facts
10,124
Population
87.7
Area (sq mi)
115
People / sq mi
New York
Time Zone
standard
ZIP Type
Who lives in ZIP 40121?
24.0
Median Age
54.6%
Male
45.4%
Female
5.3%
Foreign-Born
Hispanic or Latino is an ethnicity category from the Census Bureau and may overlap with other categories above.
Source: U.S. Census Bureau, ACS 5-Year Estimates (2023)
How much do residents earn?
$82,663
Median Household Income
+39% vs state ZIP avg
$32,370
Per Capita Income
9.0%
Poverty Rate
5.3%
Unemployment Rate
12.4 min
Mean Commute Time
How ZIP 40121 ranks among Kentucky ZIPs
Fort Knox, KY household income vs. every Kentucky ZIP code
Median household income among 646 reporting Kentucky ZIPs (this ZIP's population is too small for a reliable national-corpus placement)
$82,663 Top 12% higher than 88% of 646 Kentucky ZIPs
Each bar is a $20K-wide band; taller bars hold more Kentucky ZIPs. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count, share, and where it sits relative to this entry.
Source U.S. Census Bureau, ACS 5-Year Estimates · 2019–2023
Source: U.S. Census Bureau, ACS 5-Year Estimates (2023)
What is the education profile here?
Source: U.S. Census Bureau, ACS 5-Year Estimates (2023)
What does housing look like?
Housing stock: occupied vs vacant
2,497housing units
2,497
Total Housing Units
2,226
Occupied Units
271
Vacant Units
3.22
Avg Household Size
Occupancy Type
$1,502
Median Rent
1976
Median Year Built
Source: U.S. Census Bureau, ACS 5-Year Estimates (2023)
What businesses operate in this ZIP?
Census Bureau data shows 55 business establishments in ZIP 40121, employing approximately 1,015 people with a combined annual payroll of $55,488,000.
55
Businesses
1,015
Employees
$55.5M
Annual Payroll
7
Industry Sectors
| Industry | Establishments | % of Total |
|---|---|---|
| Professional, scientific, and technical services | 14 | 25.4% |
| Administrative and support and waste management and remediation services | 9 | 16.4% |
| Accommodation and food services | 6 | 10.9% |
| Other services (except public administration) | 6 | 10.9% |
| Retail trade | 5 | 9.1% |
| Finance and insurance | 4 | 7.3% |
| Health care and social assistance | 4 | 7.3% |
Source: U.S. Census Bureau, ZIP Code Business Patterns (ZBP), 2023. Employment figures may include noise for disclosure avoidance.
Nearby ZIP Codes
Want a side-by-side? Compare 40121 vs 40155 →
ZIP 40121 vs its nearest neighbors, by population
Resident population of this ZIP and the closest reporting ZIP codes within ~10 miles.
- 40160
Radcliff (40160)
23,574 residents
- 40175
Vine Grove (40175)
13,070 residents
- 40121
Fort Knox (40121)
10,124 residents
- 40177 1,463
West Point (40177)
1,463 residents
- 47135 1,372
Laconia (47135)
1,372 residents
- 40155 947
Muldraugh (40155)
947 residents
What this shows Among its immediate neighbors, ZIP 40121 ranks #3 by population - useful context the national average alone can't give.
ZIP 40121 vs its nearest neighbors, by median income
Median household income of this ZIP and the closest reporting ZIP codes within ~10 miles.
- 40121
Fort Knox (40121)
$82,663 median income
- 40175
Vine Grove (40175)
$77,509 median income
- 40155
Muldraugh (40155)
$60,508 median income
- 40160
Radcliff (40160)
$58,506 median income
- 40177
West Point (40177)
$50,577 median income
- 47135
Laconia (47135)
$48,611 median income
What this shows By household income, ZIP 40121 ranks the highest of 6 neighboring ZIPs, local affluence varies block to block, not just metro to metro.
Nationwide ZIPs with similar ACS profiles
Two Census-derived peer sets for ZIP 40121, both outside KY so the neighborhoods are not geographic containment (Nearby and same-county blocks stay local).
Similar population
Nearest cross-state ZIPs by resident population (10,124 here; floor ≥1,000).
Similar median household income
Nearest cross-state ZIPs by ACS median household income.
More ZIP Codes in Hardin County
Related Areas
Frequently Asked Questions
What county is ZIP code 40121 in?
ZIP code 40121 (Fort Knox) is located in Hardin County, Kentucky. Hardin County contains multiple ZIP codes, see the full list at /counties/hardin-ky.
What is the population of ZIP code 40121?
ZIP code 40121 in Fort Knox, KY has a population of 10,124 according to the Census Bureau ACS 2023 estimates.
What is the median household income in ZIP 40121?
The median household income in ZIP 40121 is $82,663, which is 8% above the national average of $76,288.
What is the demographic makeup of ZIP 40121?
The largest racial group in ZIP 40121 is White at 55.6%. Hispanic or Latino residents make up 22.7% of the population.
How many businesses are in ZIP code 40121?
ZIP code 40121 has 55 business establishments employing approximately 1,015 people, according to Census Bureau ZIP Code Business Patterns (ZBP) 2023 data.
What are the main industries in ZIP code 40121?
The top industries by establishment count in ZIP 40121 are: Professional, scientific, and technical services (14), Administrative and support and waste management and remediation services (9), Accommodation and food services (6). There are 7 industry sectors represented in total.
What is the education level in ZIP code 40121?
In ZIP code 40121, 61.3% of residents aged 25+ have a high school diploma or higher, and 48.3% hold a bachelor's degree or higher. These figures come from the Census Bureau ACS 5-Year Estimates (2023).
What is the average commute time in ZIP 40121?
The mean commute time for workers in ZIP code 40121 is 12.4 minutes according to Census ACS data. The national average is roughly 26 minutes, so commuters here spend less time traveling to work than typical.
What is the poverty rate in ZIP code 40121?
The poverty rate in ZIP code 40121 is 9.0% according to Census Bureau ACS 2023 estimates. This measures the percentage of the population living below the federal poverty threshold.
Related
Take this with you
What to do with ZIP 40121's numbers, next.
- See how ZIP 40121 compares to a neighboring ZIP code on the same Census fields Compare this ZIP
- Check where Fort Knox, KY ranks among every U.S. ZIP code on income, education, or homeownership View national rankings
- Save this ZIP to your shortlist to track alongside others you're considering View your shortlist
ZIP Code Tabulation Areas (ZCTAs) are Census Bureau approximations of USPS ZIP codes; figures describe the ZCTA area, not any single address within it.