| ZIP Codes: | 8 ZIP Codes (7 Standard, 1 PO Box, 0 Unique) [See All] |
| Area Codes: | 512 / 737 |
| Timezone: | Central (GMT -06:00) |
| Local Time: | 11:55:16 PM |
| Population: | 286,831 [See All] |
| FIPS: | 48209 |
| CBSA: | Austin-Round Rock-San Marcos, TX |
| Land Area: | 800 sq mi |
| Water Area: | 3 sq mi |
| Coordinates: | 30.0514, -97.9790 |
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286,831 residents live across 8 ZIPs covering 800 sq mi, served by 7 distinct USPS-recognized cities.
Population moved from 185,122 to 286,831 from 2014 to 2024 — a +54.9% change. 7 ZIPs gained residents, 0 lost.
The county's wealthiest ZIP 78619 (Driftwood, $183,393 median) and poorest ZIP 78666 (San Marcos, $54,737) are 16.6 miles apart — a 3.4× income gap across local geography.
Median home values vary 2.6× across this county — from $306,700 in 78666 (San Marcos) to $810,600 in 78619 (Driftwood).
Density varies 9× across the county — from 96 people/sq mi in 78676 (Wimberley) to 838 in 78640 (Kyle).
Educational attainment ranges from 29.3% bachelor's+ in 78640 (Kyle) to 66.9% in 78737 (Austin) — the breadth of educational profiles across the area.
Within Texas, this is the #19 most populous of 254 counties and ranks #3 for median household income with the #5 fastest decade growth .
On the national stage, Hays County is ranks #81 for income , and #10 for decade growth .
Weighted by population, the typical household earns about $98,660 across the county — reflecting what a typical resident sees, not a simple ZIP average.
42.6% of adults age 25+ hold a bachelor's degree or higher (76,828 of 180,213 reporting).
7 Standard delivery, 1 PO Box only, 0 single-entity Unique ZIPs serve this county.
3 ZIPs in this county where more than 60% of adults 25+ hold a bachelor's degree — typically college campuses, research enclaves, or tech corridors.
Median household income spans 3.4× between the wealthiest and poorest ZIPs — a sign of significant intra-county inequality.
Hays County grew 54.9% over the past decade — concentrated in 5 high-growth ZIPs:
| ZIP | City | Type | Population | Median Income | Area (sq mi) | 10-yr Growth |
|---|---|---|---|---|---|---|
| 78666 | San Marcos | Standard | 88,583 | $54,737 | 196.5 | 28.9% |
| 78640 | Kyle | Standard | 77,531 | $90,075 | 92.5 | 71.8% |
| 78610 | Buda | Standard | 48,319 | $119,698 | 94.1 | 79.0% |
| 78737 | Austin | Standard | 27,023 | $168,920 | 37.9 | 90.7% |
| 78620 | Dripping Springs | Standard | 22,860 | $153,477 | 173.6 | 62.1% |
| 78676 | Wimberley | Standard | 15,822 | $87,344 | 164.9 | 29.5% |
| 78619 | Driftwood | Standard | 6,693 | $183,393 | 40.0 | 75.9% |
| 78667 | San Marcos | PO Box | — | — | 0.0 | — |