Which ZIP code in St. Louis County has the lowest median age?

63134 (Saint Louis), at 28.7 (±3.9), among 44 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 St. Louis County, MO

These are the 25 ZIP codes in St. Louis County with the lowest median age, out of 44 with at least 1,000 residents. 63134 (Saint Louis, 28.7), 63105 (Saint Louis, 31.0) and 63138 (Saint Louis, 33.1) lead the list. There is no single "best" ZIP code in St. Louis 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 St. Louis County

Rank	ZIP	Mailing city	Median age	Residents	Households	Residential mailboxes
1	63134	Saint Louis	28.7 ±3.9	13,059	4,851	5,287
2	63105	Saint Louis	31.0 ±1.7	18,875	7,088	7,515
3	63138	Saint Louis	33.1 ±2.6	18,233	7,339	7,398
4	63121	Saint Louis	33.2 ±2.1	25,008	11,142	10,903
5	63074	Saint Ann	33.7 ±1.9	15,793	6,976	6,926
6	63143	Saint Louis	34.7 ±1.9	8,975	4,825	5,187
7	63130	Saint Louis	35.6 ±2.3	28,910	12,580	12,990
8	63042	Hazelwood	35.6 ±4.6	17,813	8,593	8,296
9	63137	Saint Louis	35.8 ±2.7	19,684	8,104	7,527
10	63135	Saint Louis	35.9 ±3.5	18,381	7,997	8,147
11	63144	Saint Louis	36.0 ±3.1	9,505	4,769	4,919
12	63117	Saint Louis	36.0 ±2.3	9,261	4,440	5,025
13	63136	Saint Louis	37.1 ±2.1	40,929	17,457	17,760
14	63043	Maryland Heights	37.1 ±1.7	21,924	9,402	9,703
15	63114	Saint Louis	37.5 ±1.6	33,969	15,031	15,082
16	63031	Florissant	38.0 ±2.3	50,196	19,408	19,166
17	63125	Saint Louis	38.1 ±3.3	33,294	13,820	14,726
18	63133	Saint Louis	38.6 ±2.7	6,569	3,015	3,155
19	63146	Saint Louis	38.8 ±2.2	30,678	14,551	15,543
20	63025	Eureka	39.2 ±2.2	19,508	6,911	7,352
21	63033	Florissant	39.5 ±2.0	43,056	17,660	17,609
22	63132	Saint Louis	39.5 ±2.1	14,283	5,997	6,095
23	63088	Valley Park	40.1 ±4.5	8,226	4,146	4,300
24	63021	Ballwin	40.7 ±1.3	55,666	22,131	22,762
25	63123	Saint Louis	40.9 ±1.0	49,077	21,755	22,718

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; 44 of 46 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 37,396 households, on 92 carrier routes with 38,029 residential mailboxes. Open any of them on the route map to see each carrier route's own figures before you choose.

Open 63134 on the EDDM route map

More rankings

Businesses that mail these ZIP codes

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Frequently asked questions

Which ZIP code in St. Louis County has the lowest median age?: 63134 (Saint Louis), at 28.7 (±3.9), among 44 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.