Town · New Hampshire
Merrimack, New Hampshire
Merrimack, town, in Hillsborough County, New Hampshire. Merrimack had 29,699 residents on July 1, 2025 by the Census Bureau's estimate, up 11.5% since 2020; the 2020 Census counted 26,632 and the ACS 2020-2024 5-year estimates put it at 28,164 (±27). GEOID 3301147540.
Residents, July 2025 estimate
29,699
Census Bureau estimate (no margin published)
2020 Census count: 26,632 · ACS 2020-2024: 28,164 ±27
Median household income
$127,219
±$16,220 (90% margin)
New Hampshire: $99,031
Median home value
$458,600
±$15,424 (90% margin)
New Hampshire: $402,500
Median gross rent
$1,932
±$147 (90% margin)
New Hampshire: $1,491
Where is Merrimack and what county is it in?
Merrimack is a town in Hillsborough County, New Hampshire. It covers 32.6 square miles of land, 817 residents per square mile in 2020.
One place lies inside Merrimack: East Merrimack (CDP, 5,176 in 2020).
Merrimack is in the Manchester-Nashua, NH metropolitan statistical area (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 Merrimack, and is it growing?
The Census Bureau estimates that 29,699 people lived in Merrimack on July 1, 2025, up 11.5% since 2020, faster than New Hampshire (+2.7%). The 2020 Census counted 26,632 residents. The 2020-2024 American Community Survey, a five-year sample, puts the population at 28,164 (±27).
| Measure | Merrimack | Hillsborough County | Change since 2015-2019 |
|---|---|---|---|
| Total population | 28,164±27 | 426,378 | +2,177 |
| Households | 10,844±478 | 168,740 | +851 |
| Average household size | 2.58±0.11 | 2.48 | no clear change |
| Housing units | 11,145±465 | 177,734 | +1,067 |
Merrimack's population since 2000
From 25,119 in 2000 to 29,699 in 2025: up 18.2%. The 2000, 2010 and 2020 figures are census counts, each for Merrimack 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 Merrimack?
The median resident of Merrimack is 41.5 years old; 22.0% are under 18 and 16.8% are 65 or older. The largest group is non-Hispanic white residents at 86.8%, then non-Hispanic Asian residents at 4.8%. 6.1% of residents were born outside the United States.
| Measure | Merrimack | Hillsborough County | Change since 2015-2019 |
|---|---|---|---|
| Median age | 41.5±2.2 | 41.0 | no clear change |
| Under 18 years | 22.0%±1.9 pts | 19.6% | – |
| 65 years and over | 16.8%±1.8 pts | 17.3% | – |
| Male | 49.7%±1.5 pts | 50.2% | – |
| Hispanic or Latino (any race) | 3.8%±1.7 pts | 8.5% | – |
| White alone, not Hispanic | 86.8%±2.5 pts | 80.1% | −3.9 pts |
| Black or African American alone, not Hispanic | 0.6%±0.4 pts | 2.2% | – |
| Asian alone, not Hispanic | 4.8%±2.1 pts | 4.3% | +2.8 pts |
| 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%±0.1 pts | 0.0% | – |
| Two or more races, not Hispanic | 3.3%±1.1 pts | 4.3% | – |
| Some other race alone, not Hispanic | 0.7%±0.7 pts | 0.5% | – |
| Born outside the United States | 6.1%±1.3 pts | 10.3% | no clear change |
| Speak a language other than English at home (age 5+) | 6.2%±1.5 pts | 13.9% | – |
| Civilian veterans (age 18+) | 8.7%±1.4 pts | 6.9% | – |
| With a disability | 8.6%±1.2 pts | 11.8% | – |
| No health insurance coverage | 2.5%±1.2 pts | 5.5% | no clear change |
| High school graduate or higher (age 25+) | 97.1%±0.9 pts | 93.4% | – |
| Bachelor's degree or higher (age 25+) | 50.2%±3.1 pts | 41.5% | no clear change |
| Graduate or professional degree (age 25+) | 18.2%±2.4 pts | 16.1% | – |
| Lived in the same house a year earlier | 92.0%±2.5 pts | 88.9% | – |
| Moved from another state in the past year | 2.3%±1.2 pts | 3.5% | – |
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 Merrimack earn?
Half of Merrimack's 10,844 households earn less than $127,219 a year (±$16,220), against $103,545 in Hillsborough County and $99,031 in New Hampshire. In 2015-2019 it was $131,970 in 2024 dollars; the margins of error cannot tell the two periods apart. 3.0% of residents live below the poverty line.
| Measure | Merrimack | Hillsborough County | Change since 2015-2019 |
|---|---|---|---|
| Median household income | $127,219±$16,220 | $103,545 | no clear change |
| Mean household income | $154,661±$9,778 | $132,601 | – |
| Per capita income | $60,888±$3,685 | $54,111 | no clear change |
| People below the poverty line | 3.0%±1.3 pts | 6.7% | no clear change |
| Children under 18 below the poverty line | 2.8%±2.5 pts | 8.5% | – |
| Households receiving SNAP | 2.4%±1.1 pts | 6.6% | – |
| Households with a computer | 97.8%±1.2 pts | 96.4% | – |
| Households with a broadband subscription | 95.5%±1.7 pts | 93.4% | – |
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 Merrimack?
Owners occupy 88.9% of Merrimack's occupied homes and renters 11.1%. The median owner-occupied home is valued at $458,600 by its owner (±$15,424). The median renter pays $1,932 a month including utilities, and 26.7% of renters pay 35% or more of their income on rent.
| Measure | Merrimack | Hillsborough County | Change since 2015-2019 |
|---|---|---|---|
| Median home value (owner-occupied) | $458,600±$15,424 | $421,100 | +$110,068 |
| Median gross rent | $1,932±$147 | $1,623 | no clear change |
| Renters paying 35% or more of income on rent | 26.7%±10.9 pts | 37.7% | −20.0 pts |
| Median monthly owner costs, with a mortgage | $2,483±$117 | $2,452 | – |
| Owner-occupied homes | 88.9%±2.2 pts | 67.4% | no clear change |
| Renter-occupied homes | 11.1%±2.2 pts | 32.6% | – |
| Housing units | 11,145±465 | 177,734 | +1,067 |
| Homeowner vacancy rate | 0.0%±0.4 pts | 0.2% | – |
| Rental vacancy rate | 4.3%±6.2 pts | 3.5% | – |
| Single-family detached homes | 66.6%±3.1 pts | 56.6% | – |
| Mobile homes | 1.2%±0.5 pts | 1.9% | – |
| Built 2020 or later | 2.5%±0.9 pts | 1.1% | – |
| Built 2010 to 2019 | 5.1%±1.4 pts | 5.6% | – |
| Built 1939 or earlier | 4.0%±1.8 pts | 18.3% | – |
| Households with no vehicle | 2.4%±1.3 pts | 5.2% | – |
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 many new homes is Merrimack building?
Builders took permits for 18 new housing units in Merrimack in 2025 (18 in single-family houses), 0.6 per 1,000 residents against 3.6 across New Hampshire.
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 Merrimack work and get to work?
69.3% of Merrimack's workers drive alone and 21.0% work from home. The average trip to work takes 26.5 minutes. The unemployment rate in 2020-2024 averaged 1.9%.
| Measure | Merrimack | Hillsborough County | Change since 2015-2019 |
|---|---|---|---|
| In the labor force (age 16+) | 73.9%±2.4 pts | 70.4% | – |
| Unemployment rate | 1.9%±0.8 pts | 3.1% | −1.9 pts |
| Drove alone to work | 69.3%±4.2 pts | 70.7% | – |
| Carpooled | 5.2%±1.9 pts | 7.3% | – |
| Public transportation | 0.2%±0.2 pts | 0.6% | – |
| Walked | 0.9%±0.6 pts | 1.8% | – |
| Worked from home | 21.0%±3.3 pts | 18.1% | +13.8 pts |
| Mean travel time to work | 26.5 min±2.2 | 27.3 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 Merrimack?
6 census tracts lie mostly in Merrimack (2020 census blocks). Their median household incomes run from $87,512 (Tract 141.01) to $173,382 (Tract 143.02).
| Tract | Residents, 2020-2024 | Median household income |
|---|---|---|
| Tract 142.02Hillsborough County | 7,230 | $111,439 |
| Tract 143.02Hillsborough County | 6,609 | $173,382 |
| Tract 142.01Hillsborough County | 5,771 | $160,465 |
| Tract 141.01Hillsborough County | 3,665 | $87,512 |
| Tract 141.02Hillsborough County | 2,836 | $97,337 |
| Tract 143.01Hillsborough County | 2,053 | $135,455 |
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 Merrimack) · Census block assignment files
How does Merrimack compare with other places in New Hampshire?
By the Census Bureau's July 2025 estimates, Merrimack is the 362nd-most populous of the 16,079 U.S. towns and townships that have one and the 3rd-most populous of 221 in New Hampshire.
Merrimack ranks 40th of 235 places in New Hampshire with 1,000 or more residents and a reliable estimate, by median household income.
| Measure | Rank | Of |
|---|---|---|
| Population, July 2025 estimate | 3rd | 221 |
| Growth 2020-2025 (PEP) | 2nd | 187 |
| Residents per square mile | 43rd | 241 |
| Median household income | 40th | 235 |
| Per capita income | 50th | 240 |
| Median home value | 56th | 239 |
| Median gross rent | 19th | 221 |
| Poverty rate | 152nd | 160 |
| Bachelor's degree or higher | 47th | 239 |
| Median age | 182nd | 239 |
| Owner-occupied share | 69th | 241 |
| Work from home | 55th | 214 |
| Travel time to work | 134th | 241 |
Merrimack's figures with every place in New Hampshire (CSV)
Every place in New Hampshire, sortable · Compare Merrimack 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 Merrimack?
9 of the 57 figures for Merrimack 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 Merrimack 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.