Counties in Massachusetts by housing units

Middlesex County had the highest housing units of 14 counties in 2021, at 653,621. Nantucket County had the lowest, at 12,138. The median was 204,929 and the figure for Massachusetts was 2.98 million. Source: the U.S. Census Bureau.

Highest653,621Middlesex County

Lowest12,138Nantucket County

Median204,92914 counties

Massachusetts2,979,634History

Map of counties, 2021

Under 53K
53K to 170K
170K to 240K
240K to 330K
330K and over

count, 2021. Source: U.S. Census Bureau, American Community Survey 5-year estimates, table B25001: total housing units. Boundaries: U.S. Census Bureau cartographic boundary files.

All counties, 2021

count. Source: U.S. Census Bureau, American Community Survey 5-year estimates, table B25001: total housing units. Retrieved 2026-10-12.

Full ranking

Rank	Counties	2021 count
1	Middlesex County	653,621
2	Worcester County	349,131
3	Suffolk County	346,557
4	Essex County	325,228
5	Norfolk County	289,052
6	Bristol County	242,312
7	Plymouth County	213,262
8	Hampden County	196,596
9	Barnstable County	164,523
10	Berkshire County	69,575
11	Hampshire County	65,784
12	Franklin County	34,326
13	Dukes County	17,529
14	Nantucket County	12,138

Other periods

2024
2023
2022
2021

About this ranking

All housing units, occupied and vacant: houses, apartments, mobile homes and rooms intended as separate living quarters. United States: American Community Survey five-year estimate, where the period shown is the last year of the five-year span.

A survey estimate averaged over five years, not a count on one date.

Every value in the ranking comes from the same publisher and the same period, so the counties are compared on one definition. Equal values share a rank.

How to cite

U.S. Census Bureau. American Community Survey 5-year estimates, table B25001: total housing units. https://www2.census.gov/programs-surveys/acs/summary_file/2021/table-based-SF/data/5YRData/acsdt5y2021-b25001.dat. Retrieved 2026-10-12.

Citation styles

The publisher is the author. Invokely is named only as the place the figures were read, where a style asks for it.

APA 7

U.S. Census Bureau. (2026). American Community Survey 5-year estimates, table B25001: total housing units (Counties in Massachusetts by housing units, 2021) [Data set]. Retrieved October 12, 2026, from https://www2.census.gov/programs-surveys/acs/summary_file/2021/table-based-SF/data/5YRData/acsdt5y2021-b25001.dat

MLA 9

American Community Survey 5-year estimates, table B25001: total housing units, Counties in Massachusetts by housing units, 2021. U.S. Census Bureau, 29 Jan. 2026, https://www2.census.gov/programs-surveys/acs/summary_file/2021/table-based-SF/data/5YRData/acsdt5y2021-b25001.dat. Invokely, https://invokely.ai/rankings/housing-units/massachusetts-counties?period=2021. Accessed 12 Oct. 2026.

Chicago (author-date)

U.S. Census Bureau. 2026. American Community Survey 5-year estimates, table B25001: total housing units. Counties in Massachusetts by housing units, 2021. Dataset. Accessed October 12, 2026. https://www2.census.gov/programs-surveys/acs/summary_file/2021/table-based-SF/data/5YRData/acsdt5y2021-b25001.dat. Also distributed by Invokely, https://invokely.ai/rankings/housing-units/massachusetts-counties?period=2021.

Harvard

U.S. Census Bureau (2026) American Community Survey 5-year estimates, table B25001: total housing units, Counties in Massachusetts by housing units, 2021 [Dataset]. Available at: https://www2.census.gov/programs-surveys/acs/summary_file/2021/table-based-SF/data/5YRData/acsdt5y2021-b25001.dat, via Invokely: https://invokely.ai/rankings/housing-units/massachusetts-counties?period=2021 (Accessed: 12 October 2026).

BibTeX

@misc{census_counties_in_massachusetts_by_2021,
  author = {{U.S. Census Bureau}},
  title = {{American Community Survey 5-year estimates, table B25001: total housing units: Counties in Massachusetts by housing units, 2021}},
  year = {2026},
  howpublished = {Data set},
  url = {https://www2.census.gov/programs-surveys/acs/summary_file/2021/table-based-SF/data/5YRData/acsdt5y2021-b25001.dat},
  urldate = {2026-10-12},
  note = {Accessed via Invokely, https://invokely.ai/rankings/housing-units/massachusetts-counties?period=2021. Publisher attribution: U.S. Census Bureau. American Community Survey 5-year estimates, table B25001: total housing units. https://www2.census.gov/programs-surveys/acs/summary\_file/2021/table-based-SF/data/5YRData/acsdt5y2021-b25001.dat. Retrieved 2026-10-12.},
}

RIS

TY  - DATA
AU  - U.S. Census Bureau
TI  - American Community Survey 5-year estimates, table B25001: total housing units: Counties in Massachusetts by housing units, 2021
PY  - 2026
DA  - 2026/01/29
PB  - U.S. Census Bureau
DB  - Invokely
UR  - https://www2.census.gov/programs-surveys/acs/summary_file/2021/table-based-SF/data/5YRData/acsdt5y2021-b25001.dat
L2  - https://invokely.ai/rankings/housing-units/massachusetts-counties?period=2021
Y2  - 2026/10/12
N1  - Accessed via Invokely, https://invokely.ai/rankings/housing-units/massachusetts-counties?period=2021.
N1  - Publisher attribution: U.S. Census Bureau. American Community Survey 5-year estimates, table B25001: total housing units. https://www2.census.gov/programs-surveys/acs/summary_file/2021/table-based-SF/data/5YRData/acsdt5y2021-b25001.dat. Retrieved 2026-10-12.
ER  -

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Questions

Which county has the highest housing units?

Middlesex County, with 653,621 in 2021, according to the U.S. Census Bureau.

Which county has the lowest housing units?

Nantucket County, with 12,138 in 2021.

Where does this ranking come from?

Every value comes from one source and one period, so the places are comparable: U.S. Census Bureau, American Community Survey 5-year estimates, table B25001: total housing units. Retrieved 2026-10-12.