Where American Families Cluster: ZIPs With the Highest Child Population Share

If you want to find family-dense neighborhoods, the cleanest single Census signal is the share of population under 18. National average is about 22%. Sun Belt master-planned suburbs routinely run 32–38%. A handful of Utah ZIPs exceed 40%.

Three patterns dominate

Mormon Utah: ZIPs in Utah County (Provo, Lehi, Eagle Mountain) and northern Utah suburbs run consistently above 35% under 18.

Texas master-planned communities: Frisco (75033, 75034), Katy (77494), and Round Rock (78664) all sit in the 32–38% range, driven by deliberate family-oriented suburban development plus high birth rates among Texas's young in-migrants.

Hispanic-majority urban neighborhoods: many of these ZIPs combine high household size with high child share, even in older legacy metros — South Texas, parts of Phoenix and East Los Angeles.

• National under-18 share: ~22%
• Sun Belt family-suburb range: 32–38%
• Utah ZIPs at the top: often 40%+
• Lowest under-18 share: Florida retirement ZIPs (often <12%)

Why this matters more than school rankings

A high child share is a leading indicator: more kids today means stable enrollment, more demand for family services, and a self-reinforcing cycle of family-friendly amenities. A low child share in a region with rising prices means schools may consolidate or close — a quiet risk to property value.