2020 census As of the
2020 census, Belmont had a population of 28,335. The median age was 40.3 years. 21.7% of residents were under the age of 18 and 16.1% were 65 years of age or older. For every 100 females there were 96.4 males, and for every 100 females age 18 and over there were 95.3 males age 18 and over. 22,198 people (78.3%) were 18 years old or older, while 6,137 (21.7%) were younger than 18 years old. All residents lived in urban areas, while none lived in rural areas. There were 10,705 households in Belmont, of which 35.3% had children under the age of 18 living in them. Of all households, 57.7% were married-couple households, 15.3% were households with a male householder and no spouse or partner present, and 20.7% were households with a female householder and no spouse or partner present. About 22.4% of all households were made up of individuals and 9.3% had someone living alone who was 65 years of age or older. The homeowner vacancy rate was 1.0% and the rental vacancy rate was 5.2%. Hispanic or Latino residents numbered 3,523 (12.4%); among them, 676 identified their race as
White, 22
Black or African American, 80 American Indian and Alaska Native, 68
Asian, 16 Native Hawaiian and Other Pacific Islander, 1,227 Some Other Race, and 1,434
two or more races. 1,021 identified their race as both White and Some Other Race. Among the residents who were not Hispanic or Latino, 13,572 were
White, 348 were Black or African American, 22 were American Indian and Alaska Native, 8,330 were Asian, 132 were Native Hawaiians or other Pacific Islanders, 300 were of other races, and 2,108 were of two or more races. The census reported that 25,321 people (98.0% of the population) lived in households, 394 (1.5%) lived in non-institutionalized group quarters, and 120 (0.5%) were institutionalized. There were 10,575 households, 3,251 (30.7%) had children under the age of 18 living in them, 5,630 (53.2%) were
opposite-sex married couples living together, 830 (7.8%) had a female householder with no husband or wife present, 391 (3.7%) had a male householder with no wife or husband present. There were 510 (4.8%)
unmarried opposite-sex partnerships, and 96 (0.9%)
same-sex married couples or partnerships. 2,904 households (27.5%) were one person and 997 (9.4%) had someone living alone who was 65 or older. The average household size was 2.39. There were 6,851 families (64.8% of households); the average family size was 2.95. The age distribution was 5,395 people (20.9%) under the age of 18, 1,668 people (6.5%) aged 18 to 24, 7,645 people (29.6%) aged 25 to 44, 7,284 people (28.2%) aged 45 to 64, and 3,843 people (14.9%) who were 65 or older. The median age was 40.9 years. For every 100 females, there were 95.4 males. For every 100 females age 18 and over, there were 92.5 males. There were 11,028 housing units at an average density of 2,381.8 per square mile, of the occupied units 6,280 (59.4%) were owner-occupied and 4,295 (42.0%) were rented. The homeowner vacancy rate was 0.7%; the rental vacancy rate was 5.2%. 16,473 people (63.8% of the population) lived in owner-occupied housing units and 8,848 people (34.2%) lived in rental housing units.
Income In 2023, the US Census Bureau estimated that the median household income was $207,609, and the
per capita income was $98,669. About 4.4% of families and 6.5% of the population were below the poverty line.
Recognition In May 2009, Belmont was ranked 11th on Forbes list of "America's Top 25 Towns to Live Well." ==Government==