Belmont, California population
Incorporated place · Official geographic code 0605108 · Census name: Belmont city
· Annual resident population estimate
U.S. Census Bureau · Population Estimates Program · Vintage 2025
+1,138 residents (+4.12%) since July 1, 2024.
Belmont had an estimated 28,752 residents on July 1, 2025, the 251st most populous of 483 incorporated places in California. Its population grew 4.12% between July 2024 and July 2025, compared with -0.02% for California and +0.52% for the United States.
- Population change, 2020–2025
- +491July 1 to July 1 · +1.74%
- Land-area density, 2025
- 6,210.5People per square mile · 2025 land area
- Rank in California, 2025
- 251 of 4831,397 of 19,471 nationally
Belmont population history
Open historical explorerThe six July 1 estimates in the table belong to one consistent Vintage 2025 series. The Census Bureau revises earlier years when it releases a new vintage; a figure from an older publication may differ from the value below.
Vintage 2025, July 1, 2020–2025 Intercensal, 2010–2020
The highest observed population in this annual series was 28,752 in 2025. This is a peak within 2020–2025 coverage, not an all-time record.
| Reference date | Population | Annual change |
|---|---|---|
| July 1, 2020 | 28,261 | — |
| July 1, 2021 | 27,346 | -915 |
| July 1, 2022 | 26,955 | -391 |
| July 1, 2023 | 26,913 | -42 |
| July 1, 2024 | 27,614 | +701 |
| July 1, 2025 | 28,752 | +1,138 |
Why is the April 2020 estimates base different from a census count?
The PEP estimates base here is 28,330 residents on April 1, 2020. It incorporates the Census Bureau’s corrections and geographic revisions and serves as the starting point for this annual series. It is not labeled an original 2020 census count. The chart starts at July 1, 2020, so its five-year change uses two July observations. Read about measurement types.
Belmont population by year, 2010–2020
From the April 2010 estimates base to the April 2020 census count, Belmont gained 2,434 residents (+9.4%). These Census Bureau intercensal estimates use 2020 boundaries and were released in November 2024.
| Date | Population | Annual change |
|---|---|---|
| April 1, 2010 · estimates base | 25,900 | — |
| July 1, 2010 | 25,975 | — |
| July 1, 2011 | 26,402 | +427 |
| July 1, 2012 | 26,914 | +512 |
| July 1, 2013 | 27,358 | +444 |
| July 1, 2014 | 27,742 | +384 |
| July 1, 2015 | 28,099 | +357 |
| July 1, 2016 | 28,273 | +174 |
| July 1, 2017 | 28,388 | +115 |
| July 1, 2018 | 28,473 | +85 |
| July 1, 2019 | 28,401 | -72 |
| April 1, 2020 · census count | 28,334 | — |
The April 2020 census count (28,334) and the Vintage 2025 April 2020 base (28,330) differ by 4. The gap comes from boundary changes and the Census Bureau’s revised 2020 base, not population change, so measure growth within one series. Source and download
Growth and density
Between July 1, 2020 and July 1, 2025, Belmont gained 491 residents, a 1.74% increase. The annualized change over these five elapsed years was +0.35%. Annualized change is a summary of the interval; it does not imply that the population changed at that rate in every year.
The 2025 Gazetteer reports 4.63 square miles of land. Dividing the July 1, 2025 population by that compatible land area gives 6,210.5 people per square mile. Water area is excluded. Density depends on geographic boundaries. It describes this entire place, rather than a typical neighborhood or built-up area.
Calculations use unrounded source values. Population counts are displayed as integers, percentages to two decimals and density to one decimal. Calculation methods · Growth calculator
How Belmont compares
Growth rates below use the same Vintage 2025 series for every row, so they can be compared directly. A city’s rate can differ sharply from its county’s because the county also includes other towns and unincorporated areas.
| Geography | Population · 2025 | Growth · 2024–25 | Growth · 2020–25 |
|---|---|---|---|
| Belmont | 28,752 | +4.12% | +1.74% |
| San Mateo County | 743,568 | +0.40% | -2.50% |
| California | 39,355,309 | -0.02% | -0.44% |
| United States | 341,784,857 | +0.52% | +3.08% |
The Census Bureau does not publish births, deaths or migration for incorporated places; county profiles show those components of change. Coverage details
Belmont demographics: age, race and income
The median age in Belmont is 39.8 years, compared with 37.9 in California. 69.7% of adults 25 and older hold a bachelor’s degree or higher, and the median household income is $205,297. About 6.9% of residents live below the poverty level, and 30.7% were born outside the United States.
These are American Community Survey 5-year estimates for 2020–2024. They describe the 60 months ending in December 2024, come from a sample survey with the margins of error shown, and are separate from the July 1, 2025 population estimate above.
| Characteristic | Belmont | Margin | California | U.S. |
|---|---|---|---|---|
| Age and sex | ||||
| Median age | 39.8 | ±1.2 | 37.9 | 38.9 |
| Under 18 years | 23.7% | ±2.5 | 22.0% | 22.0% |
| 65 years and over | 13.9% | ±1.6 | 15.7% | 17.2% |
| Female | 49.9% | ±2.1 | 50.1% | 50.5% |
| Race and Hispanic origin | ||||
| Hispanic or Latino (any race) | 13.1% | ±2.7 | 40.2% | 19.3% |
| White alone, not Hispanic | 45.8% | ±3.1 | 33.8% | 57.4% |
| Black alone, not Hispanic | 1.8% * | ±0.9 | 5.2% | 11.9% |
| Asian alone, not Hispanic | 30.6% | ±3.2 | 15.3% | 5.9% |
| American Indian and Alaska Native, not Hispanic | 0.3% * | ±0.4 | 0.3% | 0.5% |
| Native Hawaiian and Pacific Islander, not Hispanic | 0.0% | ±<0.1 | 0.3% | 0.2% |
| Some other race, not Hispanic | 1.3% * | ±0.8 | 0.6% | 0.6% |
| Two or more races, not Hispanic | 7.1% | ±1.4 | 4.4% | 4.3% |
| Born outside the United States | 30.7% | ±2.8 | 27.0% | 14.1% |
| Households and education | ||||
| Households | 10,500 | ±295 | 13,548,091 | 129,227,496 |
| Average household size | 2.53 | ±0.07 | 2.84 | 2.53 |
| Bachelor’s degree or higher, age 25+ | 69.7% | ±4.4 | 37.1% | 35.7% |
| Income and poverty | ||||
| Median household income | $205,297 | ±$18,232 | $99,122 | $80,734 |
| Below the poverty level | 6.9% | ±2.4 | 12.0% | 12.5% |
Margins are 90% margins of error. * The margin is large relative to the estimate (coefficient of variation above 30%); treat it as approximate. Percentages are computed from published Summary File counts with Census Bureau margin formulas. ACS survey population: 27,337; 2024 boundaries. Source and download
Geographic context
This figure covers the residents inside Belmont’s municipal boundary on July 1, 2025. It is not a metropolitan-area total, and figures for a ZIP code, school district or mailing address area cover different territory, so they usually differ. Belmont lies in San Mateo County, according to the published county/place-part relationships.
California population · State city directory · City proper versus county versus metro
Other incorporated places in San Mateo County
Largest other whole incorporated places sharing this county; their totals can include residents of neighboring counties.
| Place | Population · 2025 | Change · 2024–25 | Growth · 2024–25 | People / sq. mi. |
|---|---|---|---|---|
| San Mateo | 103,337 | +481 | +0.47% | 8,528.6 |
| Daly City | 101,261 | +168 | +0.17% | 13,237.4 |
| Redwood City | 82,178 | -283 | -0.34% | 4,250.0 |
| South San Francisco | 64,941 | +460 | +0.71% | 7,055.6 |
| San Bruno | 42,305 | +262 | +0.62% | 7,707.9 |
California incorporated places with nearby population ranks
Neighboring 2025 population ranks within California. Similar population does not imply similar density, boundaries or demographics.
| Place | Population · 2025 | Change · 2024–25 | Growth · 2024–25 | People / sq. mi. |
|---|---|---|---|---|
| Monterey | 28,953 | +78 | +0.27% | 3,349.1 |
| East Palo Alto | 28,872 | -101 | -0.35% | 11,421.1 |
| Ridgecrest | 28,333 | -53 | -0.19% | 1,358.2 |
| Brawley | 28,008 | -173 | -0.61% | 3,462.5 |
Source, citation and downloads
U.S. Census Bureau, Population Estimates Program, Vintage 2025, sub-est2025.csv, variable POPESTIMATE2025; Belmont city, California, geographic code 0605108; resident population 28,752 on July 1, 2025; boundaries January 1, 2025. https://www2.census.gov/programs-surveys/popest/datasets/2020-2025/cities/totals/sub-est2025.csv. Retrieved September 30, 2026. US Population Data snapshot pep-2025-r1, transformation 1.
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