Data / Rankings / Population density / Counties in Massachusetts

Counties in Massachusetts by population density, 2025

Suffolk County had the highest population density of 14 counties in 2025, at 5,248.2 inhabitants per km². Franklin County had the lowest, at 39 inhabitants per km². The median was 259.7 inhabitants per km² and the figure for Massachusetts was 354.1 inhabitants per km². Source: the U.S. Census Bureau.

Highest5,248.2Suffolk County
Lowest39Franklin County
Median259.714 counties
Massachusetts354.1History

All counties, 2025

CSVChart (SVG)

Suffolk CountySuffolk County: 5,248.2 inhabitants per km²5,248.2Middlesex CountyMiddlesex County: 788.3 inhabitants per km²788.3Norfolk CountyNorfolk County: 721.1 inhabitants per km²721.1Essex CountyEssex County: 648 inhabitants per km²648Bristol CountyBristol County: 414.4 inhabitants per km²414.4Plymouth CountyPlymouth County: 320.6 inhabitants per km²320.6Hampden CountyHampden County: 290.6 inhabitants per km²290.6Barnstable CountyBarnstable County: 228.8 inhabitants per km²228.8Worcester CountyWorcester County: 227.1 inhabitants per km²227.1Nantucket CountyNantucket County: 123.4 inhabitants per km²123.4Hampshire CountyHampshire County: 120.1 inhabitants per km²120.1Dukes CountyDukes County: 79.4 inhabitants per km²79.4Berkshire CountyBerkshire County: 53.4 inhabitants per km²53.4Franklin CountyFranklin County: 39 inhabitants per km²39
inhabitants per km². Source: Invokely calculation with data from U.S. Census Bureau. Retrieved 2026-10-09.

Full ranking

RankCounties2025
inhabitants per km²		Change on 2024
1Suffolk County5,248.2-0.2%
2Middlesex County788.3+0.4%
3Norfolk County721.1+0.3%
4Essex County648+0.1%
5Bristol County414.4+0.5%
6Plymouth County320.6+0.4%
7Hampden County290.6+0.2%
8Barnstable County228.8-0.2%
9Worcester County227.1+0.5%
10Nantucket County123.4+0.3%
11Hampshire County120.1-0.4%
12Dukes County79.4-0.6%
13Berkshire County53.4-0.6%
14Franklin County39-0.3%

Other periods

About this ranking

Resident population divided by land area in km². World Bank figures use mid-year population and land area excluding inland water.

United States: Census Bureau population estimates for 1 July divided by land area (water excluded) from the latest Census Gazetteer files. US tables often give people per square mile; multiply persons per km² by 2.59 to compare.

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. Population Estimates Program resident population on 1 July divided by land area from the latest Census Gazetteer files, persons per km². https://www2.census.gov/programs-surveys/popest/datasets/2020-2025/. Retrieved 2026-10-09.

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Questions

Which county has the highest population density?

Suffolk County, with 5,248.2 inhabitants per km² in 2025, according to the U.S. Census Bureau.

Which county has the lowest population density?

Franklin County, with 39 inhabitants per km² in 2025.

Where does this ranking come from?

Every value comes from one source and one period, so the places are comparable: U.S. Census Bureau, Population Estimates Program resident population on 1 July divided by land area from the latest Census Gazetteer files, persons per km². Retrieved 2026-10-09.

Population density: other rankings

Counties in Massachusetts: more rankings