San Marcos Population

1870–2026

79,808

2026 projection

17% since 2020 (increase)

020K40K60K80K18801900192019401960198020002020

Source: U.S. Census Bureau decennial counts and annual estimates. 2026 is a projection. Values between recorded years are interpolated.

Use the left and right arrow keys to inspect population observations.

Population by year

Population estimates for San Marcos. Annual change is shown as a percentage. Growth is the total change since the preceding observation.
202679,808+1,9782.54%
202577,830+1,7162.25%
202476,114+4,1095.71%
202372,005+1,4332.03%
202270,572+1,1301.63%
202169,442+1,2431.82%
202068,199+3,4475.32%
201964,752+9501.49%
201863,802+1860.29%
201763,616+1,8342.97%

Showing 10 of 31 years.

San Marcos Demographics

25.5median age

Median age

Female24.9 yrs
Male26.1 yrs

Adults

61,499
7,637 seniors · 12%53,862 other adults

Sex

Female 53.7% · 38,090Male 46.3% · 32,807

Population by age

MaleFemale85+ years, male: 20285+ years, female: 58880–84 years, male: 35780–84 years, female: 34675–79 years, male: 55175–79 years, female: 52870–74 years, male: 1,09370–74 years, female: 1,27365–69 years, male: 96965–69 years, female: 1,73060–64 years, male: 1,49960–64 years, female: 1,08255–59 years, male: 92555–59 years, female: 1,18750–54 years, male: 89750–54 years, female: 1,20745–49 years, male: 1,06945–49 years, female: 1,23840–44 years, male: 1,72540–44 years, female: 1,46435–39 years, male: 2,08235–39 years, female: 2,37730–34 years, male: 2,64630–34 years, female: 2,33525–29 years, male: 3,60325–29 years, female: 3,59320–24 years, male: 7,22920–24 years, female: 10,94515–19 years, male: 3,77515–19 years, female: 4,63310–14 years, male: 1,23810–14 years, female: 1,0015–9 years, male: 1,2285–9 years, female: 1,1850–4 years, male: 1,7190–4 years, female: 1,37885+80–8475–7970–7465–6960–6455–5950–5445–4940–4435–3930–3425–2920–2415–1910–145–90–45K5K10K10K

Hover or tap an age group to see exact counts. Use the up and down arrow keys to inspect age groups.

U.S. Census Bureau, 2024 ACS 5-year estimates · Table S0101

Race and ethnicity

Tap a square or a group below to highlight it.

Each square is about 1% of residents (roughly 709 people).

Hispanic or Latino residents can be of any race. All other groups exclude Hispanic residents.

U.S. Census Bureau, 2024 ACS 5-year estimates · Table B03002

San Marcos Income

$51,281median household income

Median household income

$51,281

Half of households earn more, half earn less

Median earnings

$39,515

Typical yearly pay for a worker 25 or older.

Poverty rate

26.9%

About 1 in 4 residents

U.S. Census Bureau, 2024 ACS 5-year estimates · Tables S1901, S1501, S1701

San Marcos Marital Status

28% of residents age 15 and older are married.

MarriedNever married
Overall
Male
Female
Marital status of residents age 15 and older
StatusOverallMaleFemale
Married28%30%25%
Never married59%59%60%
Divorced9%9%10%
Widowed3%1%4%
Separated1%1%1%

U.S. Census Bureau, 2024 ACS 5-year estimates · Table S1201

Sources

10 sources, all from the U.S. Census Bureau

Population

American Community Survey, 2024 5-year