Town · Massachusetts
Chelmsford, Massachusetts
Chelmsford, town, in Middlesex County, Massachusetts. Chelmsford had 38,549 residents on July 1, 2025 by the Census Bureau's estimate, up 6.0% since 2020; the 2020 Census counted 36,392 and the ACS 2020-2024 5-year estimates put it at 36,446 (±43). GEOID 2501713135.
Residents, July 2025 estimate
38,549
Census Bureau estimate (no margin published)
2020 Census count: 36,392 · ACS 2020-2024: 36,446 ±43
Median household income
$140,629
±$8,110 (90% margin)
Massachusetts: $103,960
Median home value
$593,700
±$17,196 (90% margin)
Massachusetts: $562,100
Median gross rent
$2,062
±$151 (90% margin)
Massachusetts: $1,762
Where is Chelmsford and what county is it in?
Chelmsford is a town in Middlesex County, Massachusetts. It covers 22.4 square miles of land, 1,626 residents per square mile in 2020.
Chelmsford is in the Boston-Cambridge-Newton, MA-NH metropolitan statistical area, which takes in 7 counties (Census Bureau delineation, July 2023).
Source: 2024 Gazetteer and 2020 place-by-county files, U.S. Census Bureau · Census reference files
How many people live in Chelmsford, and is it growing?
The Census Bureau estimates that 38,549 people lived in Chelmsford on July 1, 2025, up 6.0% since 2020, faster than Massachusetts (+1.7%). The 2020 Census counted 36,392 residents. The 2020-2024 American Community Survey, a five-year sample, puts the population at 36,446 (±43).
| Measure | Chelmsford | Middlesex County | Change since 2015-2019 |
|---|---|---|---|
| Total population | 36,446±43 | 1,638,365 | +1,320 |
| Households | 13,450±489 | 634,215 | no clear change |
| Average household size | 2.68±0.10 | 2.49 | no clear change |
| Housing units | 13,942±454 | 664,267 | no clear change |
Chelmsford's population since 2000
From 33,858 in 2000 to 38,549 in 2025: up 13.9%. The 2000, 2010 and 2020 figures are census counts, each for Chelmsford as it was drawn that year: a place that annexed land, or a community that has since incorporated, covered a different area then. The 2005 figure is the Census Bureau's intercensal estimate, revised to fit the 2000 and 2010 counts and drawn on 2010 boundaries; 2015 and 2025 are July 1 estimates made from the census before them.
Source: The 2000, 2010 and 2020 Census counts and the Census Bureau's population estimates (intercensal 2000-2010, Vintage 2020, Vintage 2025) · Census population estimates
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 Chelmsford?
The median resident of Chelmsford is 41.6 years old; 21.6% are under 18 and 18.1% are 65 or older. The largest group is non-Hispanic white residents at 77.1%, then non-Hispanic Asian residents at 10.8%. 13.5% of residents were born outside the United States.
| Measure | Chelmsford | Middlesex County | Change since 2015-2019 |
|---|---|---|---|
| Median age | 41.6±1.9 | 38.9 | −2.9 |
| Under 18 years | 21.6%±1.6 pts | 19.5% | – |
| 65 years and over | 18.1%±1.2 pts | 16.3% | – |
| Male | 48.6%±1.7 pts | 49.4% | – |
| Hispanic or Latino (any race) | 6.1%±1.6 pts | 9.3% | +2.8 pts |
| White alone, not Hispanic | 77.1%±2.6 pts | 65.1% | −8.1 pts |
| Black or African American alone, not Hispanic | 1.9%±1.0 pts | 4.7% | no clear change |
| Asian alone, not Hispanic | 10.8%±1.9 pts | 13.6% | no clear change |
| American Indian and Alaska Native alone, not Hispanic | 0.1%±0.2 pts | 0.1% | – |
| Native Hawaiian and Other Pacific Islander alone, not Hispanic | 0.0%±0.1 pts | 0.0% | – |
| Two or more races, not Hispanic | 3.3%±0.8 pts | 5.8% | – |
| Some other race alone, not Hispanic | 0.5%±0.5 pts | 1.4% | – |
| Born outside the United States | 13.5%±1.8 pts | 23.1% | +2.6 pts |
| Speak a language other than English at home (age 5+) | 17.2%±2.1 pts | 29.1% | – |
| Civilian veterans (age 18+) | 4.6%±0.7 pts | 3.3% | – |
| With a disability | 11.2%±1.3 pts | 9.9% | – |
| No health insurance coverage | 1.2%±0.4 pts | 2.4% | no clear change |
| High school graduate or higher (age 25+) | 93.8%±1.2 pts | 93.2% | – |
| Bachelor's degree or higher (age 25+) | 52.8%±3.0 pts | 59.5% | −3.7 pts |
| Graduate or professional degree (age 25+) | 24.3%±2.4 pts | 30.5% | – |
| Lived in the same house a year earlier | 91.7%±1.9 pts | 87.2% | – |
| Moved from another state in the past year | 1.8%±0.9 pts | 2.7% | – |
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 Chelmsford earn?
Half of Chelmsford's 13,450 households earn less than $140,629 a year (±$8,110), against $130,847 in Middlesex County and $103,960 in Massachusetts. In 2015-2019 it was $142,897 in 2024 dollars; the margins of error cannot tell the two periods apart. 4.7% of residents live below the poverty line.
| Measure | Chelmsford | Middlesex County | Change since 2015-2019 |
|---|---|---|---|
| Median household income | $140,629±$8,110 | $130,847 | no clear change |
| Mean household income | $162,009±$8,239 | $178,070 | – |
| Per capita income | $60,022±$3,244 | $69,556 | −$4,685 |
| People below the poverty line | 4.7%±1.3 pts | 7.7% | no clear change |
| Children under 18 below the poverty line | 3.2%±1.5 pts | 7.9% | no clear change |
| Households receiving SNAP | 10.0%±2.2 pts | 9.3% | – |
| Households with a computer | 97.5%±0.9 pts | 97.0% | – |
| Households with a broadband subscription | 95.2%±1.5 pts | 94.7% | – |
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 Chelmsford?
Owners occupy 82.1% of Chelmsford's occupied homes and renters 17.9%. The median owner-occupied home is valued at $593,700 by its owner (±$17,196). The median renter pays $2,062 a month including utilities, and 46.7% of renters pay 35% or more of their income on rent.
| Measure | Chelmsford | Middlesex County | Change since 2015-2019 |
|---|---|---|---|
| Median home value (owner-occupied) | $593,700±$17,196 | $727,800 | +$100,807 |
| Median gross rent | $2,062±$151 | $2,201 | no clear change |
| Renters paying 35% or more of income on rent | 46.7%±8.4 pts | 37.6% | no clear change |
| Median monthly owner costs, with a mortgage | $2,983±$110 | $3,224 | – |
| Owner-occupied homes | 82.1%±2.2 pts | 61.3% | no clear change |
| Renter-occupied homes | 17.9%±2.2 pts | 38.7% | – |
| Housing units | 13,942±454 | 664,267 | no clear change |
| Homeowner vacancy rate | 0.1%±0.2 pts | 0.6% | – |
| Rental vacancy rate | 6.3%±5.2 pts | 3.4% | – |
| Single-family detached homes | 66.7%±2.8 pts | 46.5% | – |
| Mobile homes | 1.9%±0.6 pts | 0.4% | – |
| Built 2020 or later | 0.6%±0.3 pts | 1.2% | – |
| Built 2010 to 2019 | 5.7%±1.5 pts | 7.3% | – |
| Built 1939 or earlier | 15.0%±2.4 pts | 32.3% | – |
| Households with no vehicle | 5.0%±1.6 pts | 10.3% | – |
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 many new homes is Chelmsford building?
Builders took permits for 17 new housing units in Chelmsford in 2025 (8 in single-family houses), 0.4 per 1,000 residents against 1.7 across Massachusetts.
Counts of units in permits a local office issued; not every permitted unit is built. A year marked with months was reported for part of the year.
Source: Building Permits Survey, annual place files 2019-2025, U.S. Census Bureau · Census Building Permits Survey
How do people in Chelmsford work and get to work?
68.8% of Chelmsford's workers drive alone and 22.8% work from home. The average trip to work takes 28.0 minutes. The unemployment rate in 2020-2024 averaged 5.3%.
| Measure | Chelmsford | Middlesex County | Change since 2015-2019 |
|---|---|---|---|
| In the labor force (age 16+) | 69.0%±2.0 pts | 69.9% | – |
| Unemployment rate | 5.3%±1.4 pts | 4.4% | no clear change |
| Drove alone to work | 68.8%±2.6 pts | 54.2% | – |
| Carpooled | 4.2%±1.1 pts | 6.3% | – |
| Public transportation | 1.0%±0.8 pts | 7.2% | – |
| Walked | 1.5%±0.7 pts | 4.2% | – |
| Worked from home | 22.8%±2.8 pts | 24.7% | +17.1 pts |
| Mean travel time to work | 28.0 min±1.7 | 29.9 min | −3.1 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
What census tracts are in Chelmsford?
8 census tracts lie mostly in Chelmsford (2020 census blocks). Their median household incomes run from $105,344 (Tract 3171.01) to $190,938 (Tract 3172.02).
| Tract | Residents, 2020-2024 | Median household income |
|---|---|---|
| Tract 3171.01Middlesex County | 6,315 | $105,344 |
| Tract 3173.02Middlesex County | 5,677 | $147,596 |
| Tract 3171.02Middlesex County | 5,287 | $130,750 |
| Tract 3171.03Middlesex County | 4,998 | $167,614 |
| Tract 3172.02Middlesex County | 4,219 | $190,938 |
| Tract 3172.03Middlesex County | 3,803 | $143,935 |
| Tract 3173.01Middlesex County | 3,456 | $128,625 |
| Tract 3172.01Middlesex County | 2,691 | $182,153 |
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 Chelmsford) · Census block assignment files
How does Chelmsford compare with other places in Massachusetts?
By the Census Bureau's July 2025 estimates, Chelmsford is the 248th-most populous of the 16,079 U.S. towns and townships that have one and the 4th-most populous of 266 in Massachusetts.
Chelmsford ranks 108th of 453 places in Massachusetts with 1,000 or more residents and a reliable estimate, by median household income.
| Measure | Rank | Of |
|---|---|---|
| Population, July 2025 estimate | 4th | 266 |
| Growth 2020-2025 (PEP) | 22nd | 292 |
| Residents per square mile | 114th | 461 |
| Median household income | 108th | 453 |
| Per capita income | 183rd | 460 |
| Median home value | 182nd | 459 |
| Median gross rent | 75th | 410 |
| Poverty rate | 240th | 338 |
| Bachelor's degree or higher | 169th | 459 |
| Median age | 348th | 461 |
| Owner-occupied share | 204th | 460 |
| Work from home | 125th | 429 |
| Travel time to work | 282nd | 459 |
Chelmsford's figures with every place in Massachusetts (CSV)
Every place in Massachusetts, sortable · Compare Chelmsford 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 Chelmsford?
6 of the 57 figures for Chelmsford 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 Chelmsford 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.