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ZIP Code Database - Facts & Stats

Data Last Updated: January 1, 2022

ZIP Codes for City of San Marcos, TX

San Marcos, TX Covers 2 ZIP Codes

ZIP CodeTypeCountyPopulationArea Code(s)
ZIP Code 78666StandardHays63,836512 / 737
ZIP Code 78667P.O. BoxHays0512 / 737

Timezone(s):Central (GMT -06:00)
Counties:HAYS, TX
Population:44,894 (More Details)
Male Population:22,305
Female Population:22,589
Median Age:23
ZIP Codes:2
Area Codes:2
Total Area:680 square miles (county)
Land Area:678 square miles (county)
Water Area:2 square miles (county)

San Marcos, TX Demographic Information *

Total population44,894
Male population22,305
Female population22,589
Median age (years)23.1
White Population35,221
Black Population2,465
Indian Population383
Asian Population697
Hawaiian Population55
Hispanic Population16,967
Median age (Male)23.5
Median age (Female)22.7
Total households17,031
Family households (families)6,485
Average household size2.27
Average family size3.03
Total housing units18,179
* Demographic data is based on 2010 Census.

San Marcos, TX Other Information

43 Cities within 30 miles of San Marcos, TX Products


  1. U.S. Postal Service [Last Updated: 1/1/2022],
  2. Internal Data Creation [Last Updated: 1/1/2022],
  3. U.S. Geological Survey [Updated as needed],
  4. U.S. Census [Updated Yearly],
  5. U.S. Census 2010 [Decennial] [Last Updated: 1/1/2010],