Belmont Population

1880–2026

28,590

2026 projection

0.9% since 2020 (increase)

05K10K15K20K25K30K18801900192019401960198020002020

Source: U.S. Census Bureau decennial counts and annual estimates, including 2010–2020 intercensal 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 Belmont. Annual change is shown as a percentage. Growth is the total change since the preceding observation.
202628,590-1620.56%
202528,752+1,1384.12%
202427,614+7012.60%
202326,913-420.16%
202226,955-3911.43%
202127,346-9893.49%
202028,335-660.23%
201928,401-720.25%
201828,473+850.30%
201728,388+1150.41%

Showing 10 of 26 years.

The 2020 row compares the April 1 Census count with the July 1, 2019 estimate (about nine months). Its Growth and Annual change therefore do not represent a full year.

Growth since 2020, compared

Belmont is growing faster than San Mateo County and California, and slower than the U.S.

  • United States+3.1%
  • Belmont+1.7%
  • California−0.4%
  • San Mateo County−2.5%

Change from July 1, 2020 to July 1, 2025 population estimates—not annualized growth or site projections.

Source: U.S. Census Bureau. U.S. totals are summed from the 50 states and D.C.; unavailable comparisons are omitted.

Belmont Demographics

39.8median age

Median age

Female40.1 yrs
Male39.5 yrs

Adults

20,871
3,813 seniors (65+) · 18% of adults17,058 other adults

Sex

Female 49.9% · 13,654Male 50.1% · 13,683

Population by age

MaleFemale85+ years, male: 20985+ years, female: 38480–84 years, male: 22580–84 years, female: 24375–79 years, male: 30075–79 years, female: 43970–74 years, male: 48170–74 years, female: 34865–69 years, male: 52765–69 years, female: 65760–64 years, male: 75360–64 years, female: 62955–59 years, male: 1,03755–59 years, female: 87650–54 years, male: 1,14650–54 years, female: 94645–49 years, male: 92145–49 years, female: 1,15540–44 years, male: 1,07140–44 years, female: 1,20235–39 years, male: 99435–39 years, female: 1,09530–34 years, male: 94530–34 years, female: 1,10125–29 years, male: 72025–29 years, female: 84120–24 years, male: 56920–24 years, female: 48015–19 years, male: 1,28915–19 years, female: 89910–14 years, male: 85610–14 years, female: 8385–9 years, male: 9805–9 years, female: 7330–4 years, male: 6600–4 years, female: 78885+80–8475–7970–7465–6960–6455–5950–5445–4940–4435–3930–3425–2920–2415–1910–145–90–45005001K1K

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 273 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

Belmont Income

$205,297median household income

Median household income

$205,297

Half of households earn more, half earn less

Median earnings

$132,761

Typical yearly pay for a worker 25 or older.

Poverty rate

6.9%

About 1 in 14 residents

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

Belmont Marital Status

58% of residents age 15 and older are married.

MarriedNever married
Overall
Male
Female
Marital status of residents age 15 and older
StatusOverallMaleFemale
Married58%58%57%
Never married31%34%29%
Divorced7%6%7%
Widowed4%2%6%
Separated<1%1%<1%

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

Sources

14 sources

Population

American Community Survey, 2024 5-year

Additional sources