City · Texas
San Marcos, Texas
San Marcos, city, mostly in Hays County (100.0% of its 2020 residents), with a part in Caldwell County, Texas. San Marcos had 77,830 residents on July 1, 2025 by the Census Bureau's estimate, up 14.9% since 2020; the 2020 Census counted 67,553 and the ACS 2020-2024 5-year estimates put it at 70,897 (±80). GEOID 4865600.
Residents, July 2025 estimate
77,830
Census Bureau estimate (no margin published)
2020 Census count: 67,553 · ACS 2020-2024: 70,897 ±80
Median household income
$51,281
±$2,567 (90% margin)
Texas: $78,476
Median home value
$310,400
±$22,179 (90% margin)
Texas: $283,800
Median gross rent
$1,322
±$39 (90% margin)
Texas: $1,403
Where is San Marcos and what county is it in?
San Marcos is a city mostly in Hays County (100.0% of its 2020 residents), with a part in Caldwell County, Texas. It covers 39.9 square miles of land, 1,692 residents per square mile in 2020.
San Marcos is in the Austin-Round Rock-San Marcos, TX metropolitan statistical area, which takes in 5 counties (Census Bureau delineation, July 2023).
| County | 2020 residents | Share |
|---|---|---|
| Hays County | 67,549 | 100.0% |
| Caldwell County | 4 | 0.0% |
| Guadalupe County | land only, no residents | – |
Source: 2024 Gazetteer and 2020 place-by-county files, U.S. Census Bureau · Census reference files
How many people live in San Marcos, and is it growing?
The Census Bureau estimates that 77,830 people lived in San Marcos on July 1, 2025, up 14.9% since 2020, faster than Texas (+8.8%). The 2020 Census counted 67,553 residents. The 2020-2024 American Community Survey, a five-year sample, puts the population at 70,897 (±80).
| Measure | San Marcos | Hays County | Change since 2015-2019 |
|---|---|---|---|
| Total population | 70,897 ±80 | 268,638 | +7,677 |
| Households | 28,013 ±869 | 99,849 | +4,859 |
| Average household size | 2.28 ±0.06 | 2.61 | −0.17 |
| Housing units | 30,349 ±818 | 104,675 | +4,877 |
San Marcos's population since 2000
From 34,733 in 2000 to 77,830 in 2025: up 124.1%. The 2000, 2010 and 2020 figures are census counts, each for San Marcos as it was drawn that year: a place that annexed land, or a community that has since incorporated, covered a different area then. The 2005 figure is the Census Bureau's intercensal estimate, revised to fit the 2000 and 2010 counts and drawn on 2010 boundaries; 2015 and 2025 are July 1 estimates made from the census before them.
Source: The 2000, 2010 and 2020 Census counts and the Census Bureau's population estimates (intercensal 2000-2010, Vintage 2020, Vintage 2025) · Census population estimates
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026); Census PEP Vintage 2025 (SUB-EST2025, CO-EST2025); 2020 Census P.L. 94-171 · Check it at data.census.gov
Who lives in San Marcos?
The median resident of San Marcos is 25.5 years old; 13.3% are under 18 and 10.8% are 65 or older. The largest group is non-Hispanic white residents at 44.6%, then Hispanic or Latino residents (of any race) at 42.2%. 9.1% of residents were born outside the United States.
| Measure | San Marcos | Hays County | Change since 2015-2019 |
|---|---|---|---|
| Median age | 25.5 ±0.4 | 34.1 | +1.3 |
| Under 18 years | 13.3% ±1.3 pts | 22.4% | – |
| 65 years and over | 10.8% ±1.4 pts | 12.2% | – |
| Male | 46.3% ±1.3 pts | 49.8% | – |
| Hispanic or Latino (any race) | 42.2% ±2.2 pts | 39.4% | no clear change |
| White alone, not Hispanic | 44.6% ±2.1 pts | 50.5% | no clear change |
| Black or African American alone, not Hispanic | 5.2% ±0.8 pts | 3.8% | no clear change |
| Asian alone, not Hispanic | 2.1% ±0.4 pts | 2.0% | no clear change |
| American Indian and Alaska Native alone, not Hispanic | 0.1% ±0.1 pts | 0.1% | – |
| Native Hawaiian and Other Pacific Islander alone, not Hispanic | 0.0% ±0.1 pts | 0.1% | – |
| Two or more races, not Hispanic | 3.9% ±0.7 pts | 3.2% | – |
| Some other race alone, not Hispanic | 1.9% ±1.5 pts | 1.0% | – |
| Born outside the United States | 9.1% ±1.9 pts | 9.8% | no clear change |
| Speak a language other than English at home (age 5+) | 27.2% ±2.3 pts | 24.7% | – |
| Civilian veterans (age 18+) | 4.7% ±0.9 pts | 6.8% | – |
| With a disability | 15.5% ±1.8 pts | 11.7% | – |
| No health insurance coverage | 16.4% ±2.2 pts | 11.6% | no clear change |
| High school graduate or higher (age 25+) | 90.5% ±1.6 pts | 92.0% | – |
| Bachelor's degree or higher (age 25+) | 38.3% ±3.6 pts | 43.2% | +4.8 pts |
| Graduate or professional degree (age 25+) | 14.6% ±2.1 pts | 15.5% | – |
| Lived in the same house a year earlier | 67.8% ±2.7 pts | 81.8% | – |
| Moved from another state in the past year | 2.2% ±0.7 pts | 2.3% | – |
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) (Data Profiles DP02, DP05) · Check it at data.census.gov
What do households in San Marcos earn?
Half of San Marcos's 28,013 households earn less than $51,281 a year (±$2,567), against $89,097 in Hays County and $78,476 in Texas. In 2015-2019 it was $49,683 in 2024 dollars; the margins of error cannot tell the two periods apart. 26.9% of residents live below the poverty line.
| Measure | San Marcos | Hays County | Change since 2015-2019 |
|---|---|---|---|
| Median household income | $51,281 ±$2,567 | $89,097 | no clear change |
| Mean household income | $66,133 ±$3,639 | $117,544 | – |
| Per capita income | $27,545 ±$1,643 | $44,565 | no clear change |
| People below the poverty line | 26.9% ±2.5 pts | 12.1% | −5.2 pts |
| Children under 18 below the poverty line | 18.1% ±7.6 pts | 8.8% | −16.0 pts |
| Households receiving SNAP | 7.0% ±1.7 pts | 5.0% | – |
| Households with a computer | 96.1% ±1.6 pts | 97.3% | – |
| Households with a broadband subscription | 85.3% ±2.3 pts | 92.9% | – |
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) (Data Profile DP03) · Check it at data.census.gov
What does housing cost in San Marcos?
Owners occupy 30.8% of San Marcos's occupied homes and renters 69.2%. The median owner-occupied home is valued at $310,400 by its owner (±$22,179). The median renter pays $1,322 a month including utilities, and 56.1% of renters pay 35% or more of their income on rent.
| Measure | San Marcos | Hays County | Change since 2015-2019 |
|---|---|---|---|
| Median home value (owner-occupied) | $310,400 ±$22,179 | $399,800 | +$99,336 |
| Median gross rent | $1,322 ±$39 | $1,495 | no clear change |
| Renters paying 35% or more of income on rent | 56.1% ±4.0 pts | 49.6% | no clear change |
| Median monthly owner costs, with a mortgage | $1,899 ±$100 | $2,289 | – |
| Owner-occupied homes | 30.8% ±2.5 pts | 64.1% | no clear change |
| Renter-occupied homes | 69.2% ±2.5 pts | 35.9% | – |
| Housing units | 30,349 ±818 | 104,675 | +4,877 |
| Homeowner vacancy rate | 2.2% ±1.9 pts | 0.7% | – |
| Rental vacancy rate | 4.9% ±1.7 pts | 3.5% | – |
| Single-family detached homes | 35.0% ±2.5 pts | 66.3% | – |
| Mobile homes | 2.5% ±0.7 pts | 5.7% | – |
| Built 2020 or later | 7.1% ±1.5 pts | 10.1% | – |
| Built 2010 to 2019 | 25.8% ±2.5 pts | 32.5% | – |
| Built 1939 or earlier | 2.3% ±0.8 pts | 1.1% | – |
| Households with no vehicle | 8.1% ±1.8 pts | 3.9% | – |
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) (Data Profile DP04) · Check it at data.census.gov
How many new homes is San Marcos building?
Builders took permits for 718 new housing units in San Marcos in 2025 (718 in single-family houses), 9.2 per 1,000 residents against 6.6 across Texas.
Counts of units in permits a local office issued; not every permitted unit is built. A year marked with months was reported for part of the year.
Source: Building Permits Survey, annual place files 2019-2025, U.S. Census Bureau · Census Building Permits Survey
How do people in San Marcos work and get to work?
68.4% of San Marcos's workers drive alone and 11.1% work from home. The average trip to work takes 24.0 minutes. The unemployment rate in 2020-2024 averaged 5.2%.
| Measure | San Marcos | Hays County | Change since 2015-2019 |
|---|---|---|---|
| In the labor force (age 16+) | 67.2% ±2.5 pts | 68.7% | – |
| Unemployment rate | 5.2% ±1.2 pts | 4.4% | −2.3 pts |
| Drove alone to work | 68.4% ±2.6 pts | 69.6% | – |
| Carpooled | 11.4% ±2.2 pts | 8.6% | – |
| Public transportation | 1.3% ±0.6 pts | 0.5% | – |
| Walked | 4.5% ±1.1 pts | 1.6% | – |
| Worked from home | 11.1% ±1.4 pts | 18.1% | +7.8 pts |
| Mean travel time to work | 24.0 min ±1.3 | 31.3 min | +1.9 min |
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) (Data Profile DP03) · Check it at data.census.gov
What census tracts are in San Marcos?
15 census tracts lie mostly in San Marcos, and 5 more reach into it (2020 census blocks). Their median household incomes run from $39,115 (Tract 103.07) to $97,629 (Tract 106.03).
| Tract | Residents, 2020-2024 | Median household income |
|---|---|---|
| Tract 102Hays County | 6,697 | $39,423 |
| Tract 104.02Hays County | 9,259 | $59,208 |
| Tract 107.03Hays County | 5,517 | $45,646 |
| Tract 103.02Hays County | 4,941 | $43,462 |
| Tract 103.05Hays County | 5,593 | $48,882 |
| Tract 105Hays County | 4,975 | $44,802 |
| Tract 104.01Hays County | 4,874 | $54,375 |
| Tract 103.09Hays County | 5,296 | $45,095 |
| Tract 103.06Hays County | 4,685 | $54,310 |
| Tract 106.01Hays County | 3,117 | $62,031 |
| Tract 106.02Hays County | 5,349 | $68,073 |
| Tract 101Hays County | 3,066 | $44,216 |
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026); 2020 block assignment files (tract share = share of the tract's census blocks in San Marcos) · Census block assignment files
How does San Marcos compare with other places in Texas?
By the Census Bureau's July 2025 estimates, San Marcos is the 487th-most populous of the 19,476 U.S. incorporated places that have one and the 55th-most populous of 1,224 in Texas.
San Marcos ranks 734th of 933 places in Texas with 1,000 or more residents and a reliable estimate, by median household income.
| Measure | Rank | Of |
|---|---|---|
| Population, July 2025 estimate | 55th | 1,224 |
| Growth 2020-2025 (PEP) | 178th | 784 |
| Residents per square mile | 263rd | 979 |
| Median household income | 734th | 933 |
| Per capita income | 647th | 978 |
| Median home value | 247th | 950 |
| Median gross rent | 290th | 852 |
| Poverty rate | 98th | 716 |
| Bachelor's degree or higher | 184th | 877 |
| Median age | 950th | 973 |
| Owner-occupied share | 969th | 973 |
| Work from home | 303rd | 557 |
| Travel time to work | 588th | 976 |
San Marcos's figures with every place in Texas (CSV)
Every place in Texas, sortable · Compare San Marcos with other places
Source: PlainCities ranks computed from the American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) and PEP Vintage 2025 · How ranks are computed
How reliable are the figures for San Marcos?
4 of the 57 figures for San Marcos on this page carry a coefficient of variation over 40% and are marked with a ring: they come from a small sample, so read them as rough.
The American Community Survey samples about one household in eight over five years, so every figure is an estimate with a 90% margin of error (shown under each value). A ring marks an estimate whose coefficient of variation is over 40%. A change is called only when the gap between the two periods is larger than their combined 90% margin (the square root of the sum of the two squared margins), the Census Bureau's test. How to read a margin of error.
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026): margins of error as published · ACS technical documentation
How these figures are made: methodology and release checks · reading a margin of error · every state · corrections
Not on this page: crime, weather and schools for San Marcos are other agencies' records. Crime: the FBI's Crime Data Explorer · climate: NOAA's U.S. Climate Normals · schools: the National Center for Education Statistics' public schools in San Marcos.