Which ZIP code in Hardin County has the lowest median age?

40121 (Fort Knox), at 24.0 (±1.7), among 12 ZIP codes with at least 1,000 residents.

Why are some ZIP codes missing?

ZIP codes with fewer than 1,000 residents are left out because their survey estimates swing too much to rank, and so are ZIP codes where the Census Bureau did not publish this figure.

Youngest ZIP codes in Hardin County, KY

These are the 12 ZIP codes in Hardin County with the lowest median age, out of 12 with at least 1,000 residents. 40121 (Fort Knox, 24.0), 42784 (Upton, 35.8) and 40160 (Radcliff, 37.5) lead the list. There is no single "best" ZIP code in Hardin County; the right one depends on who you want to reach, so the same ZIP codes are ranked several ways below.

Youngest ZIP codes in Hardin County

Rank	ZIP	Mailing city	Median age	Residents	Households	Residential mailboxes
1	40121	Fort Knox	24.0 ±1.7	8,836	2,226	2,757
2	42784	Upton	35.8 ±6.4	3,089	1,339	1,160
3	40160	Radcliff	37.5 ±1.7	23,624	9,748	10,244
4	42701	Elizabethtown	38.1 ±1.4	53,987	22,085	25,170
5	40175	Vine Grove	38.1 ±1.5	15,718	5,839	6,420
6	40177	West Point	39.4 ±7.4	1,523	658	715
7	42776	Sonora	43.1 ±11.8	2,082	775	1,120
8	42724	Cecilia	43.2 ±5.6	5,345	2,144	2,138
9	40162	Rineyville	43.3 ±6.8	6,180	2,345	2,435
10	42732	Eastview	43.7 ±14.0	1,541	666	848
11	42740	Glendale	45.3 ±6.6	1,873	807	846
12	42712	Big Clifty	53.3 ±6.0	1,714	784	894

How we ranked them

Ranked by median age of all residents, lowest first (ACS 5-year estimates, 2020–2024). ZIP codes need at least 1,000 residents to be ranked; 12 of 13 qualify.

Which of these to mail, and why

Younger ZIP codes skew toward renters, students and young families: fitness, quick-service food, apartments, entertainment and first-time-buyer offers.

The top five ZIP codes on this list hold 41,237 households, on 71 carrier routes with 45,751 residential mailboxes. Open any of them on the route map to see each carrier route's own figures before you choose.

Open 40121 on the EDDM route map

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Businesses that mail these ZIP codes

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Frequently asked questions

Which ZIP code in Hardin County has the lowest median age?: 40121 (Fort Knox), at 24.0 (±1.7), among 12 ZIP codes with at least 1,000 residents.
How is this ranking calculated?: Ranked by median age of all residents, lowest first (ACS 5-year estimates, 2020–2024).
Why are some ZIP codes missing?: ZIP codes with fewer than 1,000 residents are left out because their survey estimates swing too much to rank, and so are ZIP codes where the Census Bureau did not publish this figure.

This product uses the Census Bureau Data API but is not endorsed or certified by the Census Bureau.