County facts · Population · October 25, 2026

Massachusetts Population by County, 2025 Census Estimates

Massachusetts population by county: July 2025 Census estimates for all 14 counties, change since 2020, density, and a link to each official parcel map.

Looking for Massachusetts population by county? The Census Bureau estimates that Massachusetts had 7,154,084 residents on July 1, 2025, spread across 14 counties. Middlesex County is the most populous, with 1,669,979 people (23% of the state), and Nantucket County is the least populous, with 14,758.

The table below lists every county with its 2025 estimate, its April 2020 starting point, the change, people per square mile, and a link to its official parcel viewer.

Massachusetts population at a glance

Counties: 14
Statewide, July 1, 2025: 7,154,084 (April 1, 2020 estimates base: 7,033,112; change +120,972, +1.7%)
Most populous: Middlesex County (1,669,979); least populous: Nantucket County (14,758)
Median county: about 505,584 residents (half of the counties are smaller)
The 5 largest counties hold 69% of all Massachusetts residents
Counties with 1,000,000+ residents: 1 · 100,000+: 11 · under 10,000: 0
Statewide density: about 917 people per square mile of land

Massachusetts population by county, July 2025 (all 14)

#	County	Jul 2025	Apr 2020	% change	People per sq mi	Parcel viewer
1	Middlesex County	1,669,979	1,631,912	+2.3%	2,042	MassGIS Interactive Property Map
2	Worcester County	888,502	862,093	+3.1%	588	MassGIS Interactive Property Map
3	Essex County	826,653	809,943	+2.1%	1,678	MassGIS Interactive Property Map
4	Suffolk County	791,891	800,934	−1.1%	13,594	MassGIS Interactive Property Map
5	Norfolk County	739,749	726,021	+1.9%	1,868	MassGIS Interactive Property Map
6	Bristol County	593,640	579,295	+2.5%	1,073	MassGIS Interactive Property Map
7	Plymouth County	546,829	530,818	+3.0%	830	MassGIS Interactive Property Map
8	Hampden County	464,338	465,818	−0.3%	753	MassGIS Interactive Property Map
9	Barnstable County	233,539	229,064	+2.0%	592	MassGIS Interactive Property Map
10	Hampshire County	164,065	162,315	+1.1%	311	MassGIS Interactive Property Map
11	Berkshire County	128,224	129,026	−0.6%	138	MassGIS Interactive Property Map
12	Franklin County	70,698	71,029	−0.5%	101	MassGIS Interactive Property Map
13	Dukes County	21,219	20,593	+3.0%	206	MassGIS Interactive Property Map
14	Nantucket County	14,758	14,251	+3.6%	319	MassGIS Interactive Property Map

Percent change runs from the April 1, 2020 estimates base to July 1, 2025. People per square mile is the July 2025 estimate divided by the county's land area in the Census Bureau's 2020 Gazetteer file, so lakes and bays are left out.

How Massachusetts's population is spread out

Grouping the counties by size shows how concentrated the state is:

Residents (July 2025)	Counties	Total residents	Share of state
1,000,000 or more	1	1,669,979	23%
250,000 to 999,999	7	4,851,602	68%
100,000 to 249,999	3	525,828	7%
25,000 to 99,999	1	70,698	1%
10,000 to 24,999	2	35,977	1%

8 counties with at least 250,000 residents hold 91% of the state's population.

Most and least densely populated

The most crowded counties by people per square mile of land:

Suffolk County: 13,594 per sq mi (791,891 people on 58 sq mi)
Middlesex County: 2,042 per sq mi (1,669,979 people on 818 sq mi)
Norfolk County: 1,868 per sq mi (739,749 people on 396 sq mi)
Essex County: 1,678 per sq mi (826,653 people on 493 sq mi)
Bristol County: 1,073 per sq mi (593,640 people on 553 sq mi)

The most thinly settled:

Franklin County: 101 per sq mi (70,698 people on 699 sq mi)
Berkshire County: 138 per sq mi (128,224 people on 927 sq mi)
Dukes County: 206 per sq mi (21,219 people on 103 sq mi)
Hampshire County: 311 per sq mi (164,065 people on 527 sq mi)
Nantucket County: 319 per sq mi (14,758 people on 46 sq mi)

About these numbers

They are estimates. Between censuses the Census Bureau's Population Estimates Program updates county totals each year from births, deaths and migration records. The next full count is the 2030 census.
The base is April 1, 2020. The estimates start from an April 1, 2020 "estimates base" built from the 2020 census, which is why it is slightly different from the published census count.
Each new release revises the past. A newer vintage can change earlier years as well, so compare numbers from the same release, as this page does.
Statewide total. The counties add up exactly to the statewide figure of 7,154,084 in the same file.

Using population numbers in a land search

Big counties, busy offices. In the most populous counties, parcel maps and deed records are usually online and searchable, but recording and permit offices are busier. Allow for that if you are on a deadline.
Small counties, fewer sales. In counties with only a few thousand people, land changes hands less often, so there are fewer recent sales to compare a price with. Recorded deeds and the local assessor's sales records are the best source.
Density hints at lot size. A low people-per-square-mile figure usually means farms, ranches and timber tracts; a high one means subdivided lots. The parcel viewer shows the actual parcel lines.
Check the official map. Use the parcel viewer link in the table for boundaries, parcel numbers and owner names, then confirm anything important with the local assessor and the office that records deeds.

Sources

U.S. Census Bureau, Population Estimates Program, county totals, Vintage 2025 (April 1, 2020 estimates base and July 1, 2020–2025 estimates, with components of change). Statewide totals are the sum of the counties and match the file's state row.
U.S. Census Bureau Gazetteer files, 2020 county land and water area (for people per square mile).
Platbookmapper county GIS directory (live data file behind our county pages, pulled October 25, 2026) for each official parcel viewer.