Census-designated place · New Jersey
Hamilton Square, New Jersey
Hamilton Square, census-designated place, in Mercer County, New Jersey. Hamilton Square had 11,622 people in the ACS 2020-2024 5-year estimates (±1,008). GEOID 3429370.
Residents, 2020-2024
11,622
±1,008 (90% margin)
2020 Census count: 12,679
Median household income
$138,162
±$8,821 (90% margin)
New Jersey: $103,556
Median home value
$397,000
±$20,064 (90% margin)
New Jersey: $454,400
Median gross rent
$2,139
±$434 (90% margin)
New Jersey: $1,720
Where is Hamilton Square and what county is it in?
Hamilton Square is a census-designated place: an unincorporated community the Census Bureau draws for counting, with no city government of its own, in Mercer County, New Jersey. It covers 4.3 square miles of land, 2,965 residents per square mile in 2020.
Hamilton Square is in the Trenton-Princeton, NJ metropolitan statistical area (Census Bureau delineation, July 2023).
Hamilton Square lies entirely within Hamilton Township (Mercer County), a township with its own local government (2020 census blocks).
Source: 2024 Gazetteer and 2020 place-by-county files, U.S. Census Bureau · Census reference files
How many people live in Hamilton Square, and is it growing?
The 2020-2024 American Community Survey puts Hamilton Square's population at 11,622 (±1,008). The 2020 Census counted 12,679 residents.
The Census Bureau publishes yearly population estimates for incorporated places only; Hamilton Square is a census-designated place, so its figures come from the ACS and the 2020 Census.
| Measure | Hamilton Square | Mercer County | Change since 2015-2019 |
|---|---|---|---|
| Total population | 11,622 ±1,008 | 385,864 | no clear change |
| Households | 4,265 ±386 | 144,114 | no clear change |
| Average household size | 2.67 ±0.16 | 2.56 | no clear change |
| Housing units | 4,367 ±381 | 151,138 | no clear change |
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 Hamilton Square?
The median resident of Hamilton Square is 44.9 years old; 18.6% are under 18 and 23.2% are 65 or older. The largest group is non-Hispanic white residents at 80.0%, then Hispanic or Latino residents (of any race) at 9.4%. 12.7% of residents were born outside the United States.
| Measure | Hamilton Square | Mercer County | Change since 2015-2019 |
|---|---|---|---|
| Median age | 44.9 ±3.1 | 39.5 | no clear change |
| Under 18 years | 18.6% ±2.9 pts | 22.0% | – |
| 65 years and over | 23.2% ±3.0 pts | 16.0% | – |
| Male | 51.3% ±2.5 pts | 49.4% | – |
| Hispanic or Latino (any race) | 9.4% ±4.8 pts | 23.1% | no clear change |
| White alone, not Hispanic | 80.0% ±5.2 pts | 42.7% | no clear change |
| Black or African American alone, not Hispanic | 3.3% ±2.8 pts | 17.9% | – |
| Asian alone, not Hispanic | 5.0% ±2.6 pts | 12.3% | no clear change |
| American Indian and Alaska Native alone, not Hispanic | 0.0% ±0.1 pts | 0.1% | – |
| Native Hawaiian and Other Pacific Islander alone, not Hispanic | 0.0% ±0.4 pts | 0.0% | – |
| Two or more races, not Hispanic | 2.2% ±1.3 pts | 3.4% | – |
| Some other race alone, not Hispanic | 0.0% ±0.4 pts | 0.5% | – |
| Born outside the United States | 12.7% ±2.5 pts | 27.0% | +4.4 pts |
| Speak a language other than English at home (age 5+) | 16.2% ±3.9 pts | 35.7% | – |
| Civilian veterans (age 18+) | 4.2% ±1.9 pts | 3.4% | – |
| With a disability | 10.2% ±2.4 pts | 10.7% | – |
| No health insurance coverage | 2.9% ±1.5 pts | 7.9% | no clear change |
| High school graduate or higher (age 25+) | 94.8% ±2.1 pts | 89.4% | – |
| Bachelor's degree or higher (age 25+) | 46.4% ±4.9 pts | 45.4% | no clear change |
| Graduate or professional degree (age 25+) | 16.0% ±3.9 pts | 21.2% | – |
| Lived in the same house a year earlier | 94.7% ±2.4 pts | 88.0% | – |
| Moved from another state in the past year | 1.6% ±1.5 pts | 2.6% | – |
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 Hamilton Square earn?
Half of Hamilton Square's 4,265 households earn less than $138,162 a year (±$8,821), against $100,645 in Mercer County and $103,556 in New Jersey. In 2015-2019 it was $139,780 in 2024 dollars; the margins of error cannot tell the two periods apart. 2.2% of residents live below the poverty line.
| Measure | Hamilton Square | Mercer County | Change since 2015-2019 |
|---|---|---|---|
| Median household income | $138,162 ±$8,821 | $100,645 | no clear change |
| Mean household income | $149,291 ±$9,265 | $142,368 | – |
| Per capita income | $55,175 ±$3,393 | $53,765 | no clear change |
| People below the poverty line | 2.2% ±1.1 pts | 10.3% | no clear change |
| Children under 18 below the poverty line | 0.9% ±1.4 pts | 13.2% | – |
| Households receiving SNAP | 2.0% ±1.5 pts | 9.3% | – |
| Households with a computer | 97.6% ±1.5 pts | 95.6% | – |
| Households with a broadband subscription | 96.3% ±2.2 pts | 91.4% | – |
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 Hamilton Square?
Owners occupy 95.6% of Hamilton Square's occupied homes and renters 4.4%. The median owner-occupied home is valued at $397,000 by its owner (±$20,064). The median renter pays $2,139 a month including utilities.
| Measure | Hamilton Square | Mercer County | Change since 2015-2019 |
|---|---|---|---|
| Median home value (owner-occupied) | $397,000 ±$20,064 | $377,700 | +$24,223 |
| Median gross rent | $2,139 ±$434 | $1,623 | +$720 |
| Renters paying 35% or more of income on rent | 34.6% ±26.4 pts | 41.3% | – |
| Median monthly owner costs, with a mortgage | $2,655 ±$108 | $2,615 | – |
| Owner-occupied homes | 95.6% ±2.3 pts | 62.2% | no clear change |
| Renter-occupied homes | 4.4% ±2.3 pts | 37.8% | – |
| Housing units | 4,367 ±381 | 151,138 | no clear change |
| Homeowner vacancy rate | 0.0% ±1.1 pts | 0.4% | – |
| Rental vacancy rate | 6.0% ±11.1 pts | 2.9% | – |
| Single-family detached homes | 90.9% ±4.0 pts | 47.5% | – |
| Mobile homes | 0.0% ±1.0 pts | 0.5% | – |
| Built 2020 or later | 0.2% ±0.4 pts | 0.9% | – |
| Built 2010 to 2019 | 2.8% ±1.9 pts | 4.8% | – |
| Built 1939 or earlier | 4.0% ±1.8 pts | 17.9% | – |
| Households with no vehicle | 2.7% ±1.8 pts | 11.2% | – |
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 do people in Hamilton Square work and get to work?
66.5% of Hamilton Square's workers drive alone and 19.4% work from home. The average trip to work takes 25.5 minutes. The unemployment rate in 2020-2024 averaged 3.4%.
| Measure | Hamilton Square | Mercer County | Change since 2015-2019 |
|---|---|---|---|
| In the labor force (age 16+) | 64.2% ±4.3 pts | 65.3% | – |
| Unemployment rate | 3.4% ±1.5 pts | 6.3% | no clear change |
| Drove alone to work | 66.5% ±5.1 pts | 60.2% | – |
| Carpooled | 11.0% ±4.6 pts | 8.7% | – |
| Public transportation | 1.6% ±1.1 pts | 4.6% | – |
| Walked | 1.1% ±0.9 pts | 3.6% | – |
| Worked from home | 19.4% ±5.1 pts | 19.5% | +15.3 pts |
| Mean travel time to work | 25.5 min ±2.4 | 27.1 min | no clear change |
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 Hamilton Square?
2 census tracts lie mostly in Hamilton Square, and 2 more reach into it (2020 census blocks). Their median household incomes run from $134,257 (Tract 30.02) to $139,167 (Tract 30.07).
| Tract | Residents, 2020-2024 | Median household income |
|---|---|---|
| Tract 30.02Mercer County | 5,852 | $134,257 |
| Tract 30.07Mercer County | 2,901 | $139,167 |
| Tract 30.06Mercer County | 4,956 | $137,982 |
| Tract 30.08Mercer County | 5,342 | $133,110 |
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 Hamilton Square) · Census block assignment files
How does Hamilton Square compare with other places in New Jersey?
Hamilton Square ranks 235th of 771 places in New Jersey with 1,000 or more residents and a reliable estimate, by median household income.
| Measure | Rank | Of |
|---|---|---|
| Population (ACS 2020-2024) | 248th | 787 |
| Residents per square mile | 292nd | 787 |
| Median household income | 235th | 771 |
| Per capita income | 383rd | 785 |
| Median home value | 469th | 777 |
| Median gross rent | 164th | 701 |
| Poverty rate | 520th | 539 |
| Bachelor's degree or higher | 373rd | 780 |
| Median age | 261st | 786 |
| Owner-occupied share | 63rd | 777 |
| Work from home | 284th | 695 |
| Travel time to work | 637th | 787 |
Hamilton Square's figures with every place in New Jersey (CSV)
Every place in New Jersey, sortable · Compare Hamilton Square 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 Hamilton Square?
16 of the 57 figures for Hamilton Square 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 Hamilton Square 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' school search.