Census tract · Middlesex County
Census Tract 3685, Middlesex County, Massachusetts
Census Tract 3685, GEOID 25017368500, in Middlesex County, Massachusetts, entirely within Waltham. 3,355 residents in the ACS 2020-2024 5-year estimates (±373); the 2020 Census counted 3,419.
Residents, 2020-2024
3,355
±373 (90% margin)
2020 Census count: 3,419
Median household income
$93,182
±$21,738 (90% margin)
Middlesex County: $130,847
Median home value
$1,038,800
±$361,159 (90% margin)
Middlesex County: $727,800
Median gross rent
$1,825
±$227 (90% margin)
Middlesex County: $2,201
Where is Census Tract 3685?
Census Tract 3685 is one of 357 census tracts in Middlesex County, Massachusetts. It covers 0.18 square miles of land, 18,994 residents per square mile in 2020. Its GEOID, 25017368500, names it uniquely (how tract numbers and GEOIDs work).
| Place | Share of the tract |
|---|---|
| Waltham | 100% |
4 census tracts border Census Tract 3685: Tract 3684 ($131,250), Tract 3686 ($125,625), Tract 3687 and Tract 3688 ($104,608). The figure in brackets is each tract's median household income.
Whether a tract counts as low- or moderate-income for bank lending (the Community Reinvestment Act) is set by the FFIEC against its metro area's family income: look it up in the FFIEC census geocoder.
Source: 2024 Gazetteer and 2020 block assignment files, U.S. Census Bureau · Census reference files
How many people live in Census Tract 3685?
The 2020-2024 American Community Survey puts Census Tract 3685's population at 3,355 (±373) in 1,978 households; the 2020 Census counted 3,419 residents and 1,992 housing units.
| Measure | Tract 3685 | Waltham |
|---|---|---|
| Total population | 3,355±373 | 64,902 |
| Households | 1,978±241 | 25,498 |
| Average household size | 1.69±0.09 | 2.23 |
| Housing units | 2,112±227 | 26,728 |
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026); 2020 Census P.L. 94-171 · Check it at data.census.gov
Who lives in Census Tract 3685?
The median resident of Census Tract 3685 is 32.8 years old; 8.0% are under 18 and 15.0% are 65 or older. The largest group is non-Hispanic white residents at 56.4%, then non-Hispanic Asian residents at 20.4%. 24.5% of residents were born outside the United States.
| Measure | Tract 3685 | Waltham |
|---|---|---|
| Median age | 32.8±1.0 | 34.4 |
| Under 18 years | 8.0%±2.1 pts | 13.6% |
| 65 years and over | 15.0%±5.9 pts | 15.8% |
| Hispanic or Latino (any race) | 8.1%±4.6 pts | 15.9% |
| White alone, not Hispanic | 56.4%±9.9 pts | 57.6% |
| Black or African American alone, not Hispanic | 5.6%±5.5 pts | 8.3% |
| Asian alone, not Hispanic | 20.4%±7.3 pts | 12.6% |
| American Indian and Alaska Native alone, not Hispanic | 1.0%±1.1 pts | 0.3% |
| Native Hawaiian and Other Pacific Islander alone, not Hispanic | 0.6%±0.9 pts | 0.1% |
| Two or more races, not Hispanic | 4.1%±3.7 pts | 4.3% |
| Some other race alone, not Hispanic | 3.7%±3.7 pts | 0.9% |
| Born outside the United States | 24.5%±6.5 pts | 26.3% |
| Speak a language other than English at home (age 5+) | 22.0%±5.9 pts | 32.3% |
| Civilian veterans (age 18+) | 2.4%±1.4 pts | 2.6% |
| With a disability | 11.6%±4.0 pts | 10.7% |
| No health insurance coverage | 4.1%±3.6 pts | 2.9% |
| High school graduate or higher (age 25+) | 93.6%±3.2 pts | 93.3% |
| Bachelor's degree or higher (age 25+) | 75.1%±8.1 pts | 57.3% |
| Graduate or professional degree (age 25+) | 40.4%±10.7 pts | 27.9% |
| Lived in the same house a year earlier | 66.8%±9.6 pts | 83.0% |
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 Census Tract 3685 earn?
Half of the 1,978 households in Census Tract 3685 earn less than $93,182 a year (±$21,738), against $130,847 across Middlesex County: 296th highest of the county's 350 tracts with a reliable estimate. 10.4% of residents live below the poverty line.
| Measure | Tract 3685 | Waltham |
|---|---|---|
| Median household income | $93,182±$21,738 | $120,216 |
| Mean household income | $112,671±$13,516 | $145,664 |
| Per capita income | $66,422±$7,009 | $58,449 |
| People below the poverty line | 10.4%±3.2 pts | 9.4% |
| Children under 18 below the poverty line | 0.0%±14.6 pts | 7.6% |
| Households receiving SNAP | 6.9%±4.3 pts | 7.0% |
| Households with a computer | 96.9%±2.1 pts | 95.6% |
| Households with a broadband subscription | 89.5%±7.7 pts | 94.0% |
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 Census Tract 3685?
Owners occupy 16.1% of Census Tract 3685's occupied homes and renters 83.9%. The median owner-occupied home is valued at $1,038,800 by its owner (±$361,159). The median renter pays $1,825 a month including utilities, and 36.6% of renters pay 35% or more of their income on rent.
| Measure | Tract 3685 | Waltham |
|---|---|---|
| Median home value (owner-occupied) | $1,038,800±$361,159 | $748,700 |
| Median gross rent | $1,825±$227 | $2,268 |
| Renters paying 35% or more of income on rent | 36.6%±8.5 pts | 35.7% |
| Median monthly owner costs, with a mortgage | $3,736±$186 | $3,076 |
| Owner-occupied homes | 16.1%±5.6 pts | 49.7% |
| Renter-occupied homes | 83.9%±5.6 pts | 50.3% |
| Housing units | 2,112±227 | 26,728 |
| Single-family detached homes | 3.6%±2.4 pts | 37.0% |
| Mobile homes | 0.0%±2.0 pts | 0.2% |
| Built 2020 or later | 8.2%±5.6 pts | 1.1% |
| Built 2010 to 2019 | 14.1%±6.3 pts | 6.4% |
| Built 1939 or earlier | 22.5%±6.3 pts | 28.3% |
| Households with no vehicle | 17.7%±5.6 pts | 8.6% |
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 Census Tract 3685 get to work?
46.4% of Census Tract 3685's workers drive alone and 35.0% work from home. The average trip to work takes 26.1 minutes.
| Measure | Tract 3685 | Waltham |
|---|---|---|
| In the labor force (age 16+) | 74.6%±6.4 pts | 68.5% |
| Unemployment rate | 4.5%±3.0 pts | 3.7% |
| Drove alone to work | 46.4%±6.4 pts | 53.0% |
| Carpooled | 5.7%±3.5 pts | 9.5% |
| Public transportation | 7.7%±5.9 pts | 4.5% |
| Walked | 3.0%±3.0 pts | 6.2% |
| Worked from home | 35.0%±7.5 pts | 24.2% |
| Mean travel time to work | 26.1 min±2.8 | 24.7 min |
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
How does Census Tract 3685 compare with the other tracts in Middlesex County?
Among Middlesex County's tracts with a reliable estimate, Census Tract 3685 ranks as shown below (1 = highest).
| Measure | In Middlesex County | In Waltham |
|---|---|---|
| Population | 272nd of 354 | 12th of 13 |
| Residents per square mile | 56th of 357 | 1st of 13 |
| Median household income | 296th of 350 | 9th of 11 |
| Per capita income | 187th of 354 | 6th of 13 |
| Median home value | 60th of 350 | 1st of 13 |
| Median gross rent | 240th of 327 | 10th of 12 |
| Poverty rate | 88th of 223 | 5th of 9 |
| Bachelor's degree or higher | 105th of 354 | 1st of 13 |
| Median age | 302nd of 354 | 10th of 13 |
| Owner-occupied share | 340th of 351 | 12th of 13 |
The tracts next to it on Middlesex County's income ladder
| Tract | Rank | Median household income |
|---|---|---|
| Tract 3501.07 | 293rd | $94,535±$52,193 · within the margin of this tract |
| Tract 3114 | 294th | $94,174±$7,990 · within the margin of this tract |
| Tract 3302.02 | 295th | $93,385±$21,741 · within the margin of this tract |
| Tract 3685 | 296th | $93,182±$21,738 |
| Tract 3397 | 297th | $92,809±$14,949 · within the margin of this tract |
| Tract 3416 | 298th | $92,768±$20,418 · within the margin of this tract |
| Tract 3419.01 | 299th | $92,109±$28,310 · within the margin of this tract |
"Within the margin": the two incomes differ by less than their combined 90% margins, so the survey cannot say which is higher and the ranks between them are not firm.
Source: PlainCities ranks computed from the American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) · How ranks are computed
How reliable are the figures for Census Tract 3685?
1 of the 18 figures for Census Tract 3685 on this page carries a coefficient of variation over 40% and is marked with a ring: they come from a small sample, so read them as rough.
A census tract's figures rest on a few hundred sampled households over five years, so its margins are wider than a city's. Two tracts differ only when the gap between them is larger than their combined 90% margin (the square root of the sum of the two squared margins). 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 · Check it at data.census.gov
How these figures are made: methodology and release checks · reading a margin of error · every state · corrections