Census-designated place · New Jersey
Blackwells Mills, New Jersey
Blackwells Mills, census-designated place, in Somerset County, New Jersey. Blackwells Mills had 10,301 people in the ACS 2020-2024 5-year estimates (±972). GEOID 3406025.
Residents, 2020-2024
10,301
±972 (90% margin)
2020 Census count: 9,473
Median household income
$250,000 or more
The survey's top or bottom value; no margin is published
New Jersey: $103,556
Median home value
$735,000
±$39,664 (90% margin)
New Jersey: $454,400
Median gross rent
$3,206
±$134 (90% margin)
New Jersey: $1,720
Where is Blackwells Mills and what county is it in?
Blackwells Mills is a census-designated place: an unincorporated community the Census Bureau draws for counting, with no city government of its own, in Somerset County, New Jersey. It covers 7.7 square miles of land, 1,233 residents per square mile in 2020.
Blackwells Mills is in the New York-Newark-Jersey City, NY-NJ metropolitan statistical area, which takes in 22 counties (Census Bureau delineation, July 2023).
Blackwells Mills lies mostly within Hillsborough Township and reaches into Franklin Township (Somerset County), towns or townships with their 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 Blackwells Mills, and is it growing?
The 2020-2024 American Community Survey puts Blackwells Mills's population at 10,301 (±972). The 2020 Census counted 9,473 residents.
The Census Bureau publishes yearly population estimates for incorporated places only; Blackwells Mills is a census-designated place, so its figures come from the ACS and the 2020 Census.
| Measure | Blackwells Mills | Somerset County | Change since 2015-2019 |
|---|---|---|---|
| Total population | 10,301 ±972 | 349,846 | +9,617 |
| Households | 3,078 ±257 | 130,802 | +2,866 |
| Average household size | 3.33 ±0.16 | 2.64 | no clear change |
| Housing units | 3,078 ±257 | 133,639 | +2,866 |
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 Blackwells Mills?
The median resident of Blackwells Mills is 40.2 years old; 27.1% are under 18 and 12.9% are 65 or older. The largest group is non-Hispanic white residents at 53.8%, then non-Hispanic Asian residents at 29.7%. 23.1% of residents were born outside the United States.
| Measure | Blackwells Mills | Somerset County | Change since 2015-2019 |
|---|---|---|---|
| Median age | 40.2 ±3.1 | 41.8 | −12.3 |
| Under 18 years | 27.1% ±3.4 pts | 21.2% | – |
| 65 years and over | 12.9% ±1.9 pts | 17.0% | – |
| Male | 49.2% ±2.9 pts | 49.3% | – |
| Hispanic or Latino (any race) | 5.5% ±3.8 pts | 17.6% | – |
| White alone, not Hispanic | 53.8% ±5.9 pts | 49.3% | no clear change |
| Black or African American alone, not Hispanic | 4.4% ±3.6 pts | 9.3% | – |
| Asian alone, not Hispanic | 29.7% ±5.1 pts | 19.6% | – |
| American Indian and Alaska Native alone, not Hispanic | 0.0% ±0.4 pts | 0.0% | – |
| Native Hawaiian and Other Pacific Islander alone, not Hispanic | 0.0% ±0.4 pts | 0.0% | – |
| Two or more races, not Hispanic | 6.5% ±3.4 pts | 3.6% | – |
| Some other race alone, not Hispanic | 0.0% ±0.1 pts | 0.7% | – |
| Born outside the United States | 23.1% ±3.9 pts | 27.9% | no clear change |
| Speak a language other than English at home (age 5+) | 29.3% ±5.0 pts | 34.7% | – |
| Civilian veterans (age 18+) | 2.4% ±1.5 pts | 3.2% | – |
| With a disability | 6.4% ±1.8 pts | 8.6% | – |
| No health insurance coverage | 0.7% ±0.6 pts | 5.4% | – |
| High school graduate or higher (age 25+) | 96.6% ±1.4 pts | 94.0% | – |
| Bachelor's degree or higher (age 25+) | 76.2% ±4.8 pts | 57.8% | −16.8 pts |
| Graduate or professional degree (age 25+) | 40.0% ±4.7 pts | 26.6% | – |
| Lived in the same house a year earlier | 91.5% ±4.1 pts | 90.9% | – |
| Moved from another state in the past year | 1.5% ±1.5 pts | 1.5% | – |
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 Blackwells Mills earn?
Half of Blackwells Mills's 3,078 households earn less than $250,000 or more a year (), against $140,374 in Somerset County and $103,556 in New Jersey. In 2015-2019 it was $241,716 in 2024 dollars; the margins of error cannot tell the two periods apart.
| Measure | Blackwells Mills | Somerset County | Change since 2015-2019 |
|---|---|---|---|
| Median household income | $250,000 or more | $140,374 | no clear change |
| Mean household income | $289,939 ±$24,872 | $191,543 | – |
| Per capita income | $84,946 ±$6,953 | $72,193 | no clear change |
| People below the poverty line | 1.7% ±1.3 pts | 5.4% | – |
| Children under 18 below the poverty line | 1.9% ±3.0 pts | 6.7% | – |
| Households receiving SNAP | 1.3% ±1.4 pts | 3.7% | – |
| Households with a computer | 99.4% ±0.9 pts | 97.7% | – |
| Households with a broadband subscription | 99.8% ±0.3 pts | 95.8% | – |
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 Blackwells Mills?
Owners occupy 95.1% of Blackwells Mills's occupied homes and renters 4.9%. The median owner-occupied home is valued at $735,000 by its owner (±$39,664). The median renter pays $3,206 a month including utilities.
| Measure | Blackwells Mills | Somerset County | Change since 2015-2019 |
|---|---|---|---|
| Median home value (owner-occupied) | $735,000 ±$39,664 | $552,100 | – |
| Median gross rent | $3,206 ±$134 | $2,033 | – |
| Renters paying 35% or more of income on rent | 49.3% ±50.7 pts | 40.5% | – |
| Median monthly owner costs, with a mortgage | $4,000 or more | $3,156 | – |
| Owner-occupied homes | 95.1% ±3.6 pts | 74.3% | no clear change |
| Renter-occupied homes | 4.9% ±3.6 pts | 25.7% | – |
| Housing units | 3,078 ±257 | 133,639 | +2,866 |
| Homeowner vacancy rate | 0.0% ±1.5 pts | 0.3% | – |
| Rental vacancy rate | 0.0% ±25.5 pts | 2.0% | – |
| Single-family detached homes | 97.3% ±2.5 pts | 57.8% | – |
| Mobile homes | 0.0% ±1.4 pts | 0.2% | – |
| Built 2020 or later | 0.6% ±1.0 pts | 1.3% | – |
| Built 2010 to 2019 | 6.5% ±3.1 pts | 6.1% | – |
| Built 1939 or earlier | 2.3% ±2.0 pts | 9.3% | – |
| Households with no vehicle | 1.3% ±1.3 pts | 4.0% | – |
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 Blackwells Mills work and get to work?
64.3% of Blackwells Mills's workers drive alone and 29.9% work from home. The average trip to work takes 33.9 minutes. The unemployment rate in 2020-2024 averaged 4.8%.
| Measure | Blackwells Mills | Somerset County | Change since 2015-2019 |
|---|---|---|---|
| In the labor force (age 16+) | 69.1% ±4.2 pts | 70.0% | – |
| Unemployment rate | 4.8% ±2.4 pts | 4.7% | – |
| Drove alone to work | 64.3% ±5.8 pts | 63.8% | – |
| Carpooled | 3.9% ±2.1 pts | 6.5% | – |
| Public transportation | 1.1% ±0.9 pts | 3.4% | – |
| Walked | 0.0% ±0.9 pts | 1.2% | – |
| Worked from home | 29.9% ±6.0 pts | 22.7% | – |
| Mean travel time to work | 33.9 min ±2.4 | 31.4 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 Blackwells Mills?
1 census tract lies mostly in Blackwells Mills, and 2 more reach into it (2020 census blocks).
| Tract | Residents, 2020-2024 | Median household income |
|---|---|---|
| Tract 538.07Somerset County | 7,294 | $250,000 or more |
| Tract 534.05Somerset County | 4,298 | $184,338 |
| Tract 538.06Somerset County | 2,399 | $187,031 |
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 Blackwells Mills) · Census block assignment files
How does Blackwells Mills compare with other places in New Jersey?
Blackwells Mills ranks 1st 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) | 282nd | 787 |
| Residents per square mile | 528th | 787 |
| Median household income | 1st | 771 |
| Per capita income | 91st | 785 |
| Median home value | 105th | 777 |
| Median gross rent | 29th | 701 |
| Bachelor's degree or higher | 44th | 780 |
| Median age | 546th | 786 |
| Owner-occupied share | 70th | 777 |
| Work from home | 72nd | 695 |
| Travel time to work | 182nd | 787 |
Blackwells Mills's figures with every place in New Jersey (CSV)
Every place in New Jersey, sortable · Compare Blackwells Mills 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 Blackwells Mills?
20 of the 57 figures for Blackwells Mills 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 Blackwells Mills 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.