Data / Rankings / Population density / Counties in Massachusetts

Counties in Massachusetts by population density

Suffolk County had the highest population density of 14 counties in 2020, at 5,244.8 inhabitants per km². Franklin County had the lowest, at 39.2 inhabitants per km². The median was 256.8 inhabitants per km² and the figure for Massachusetts was 345.7 inhabitants per km². Source: the U.S. Census Bureau.

Highest5,244.8Suffolk County
Lowest39.2Franklin County
Median256.814 counties
Massachusetts345.7History

All counties, 2020

CSVChart (SVG)

Suffolk CountySuffolk County: 5,244.8 inhabitants per km²5,244.8Middlesex CountyMiddlesex County: 766.8 inhabitants per km²766.8Norfolk CountyNorfolk County: 705.4 inhabitants per km²705.4Essex CountyEssex County: 633.3 inhabitants per km²633.3Bristol CountyBristol County: 402.6 inhabitants per km²402.6Plymouth CountyPlymouth County: 309.8 inhabitants per km²309.8Hampden CountyHampden County: 290.1 inhabitants per km²290.1Barnstable CountyBarnstable County: 223.4 inhabitants per km²223.4Worcester CountyWorcester County: 219 inhabitants per km²219Nantucket CountyNantucket County: 119 inhabitants per km²119Hampshire CountyHampshire County: 108.8 inhabitants per km²108.8Dukes CountyDukes County: 77 inhabitants per km²77Berkshire CountyBerkshire County: 54.1 inhabitants per km²54.1Franklin CountyFranklin County: 39.2 inhabitants per km²39.2
inhabitants per km². Source: Invokely calculation with data from U.S. Census Bureau. Retrieved 2026-10-09.

Full ranking

RankCounties2020
inhabitants per km²
1Suffolk County5,244.8
2Middlesex County766.8
3Norfolk County705.4
4Essex County633.3
5Bristol County402.6
6Plymouth County309.8
7Hampden County290.1
8Barnstable County223.4
9Worcester County219
10Nantucket County119
11Hampshire County108.8
12Dukes County77
13Berkshire County54.1
14Franklin County39.2

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.

Use this data in your AI agent

Invokely serves this figure to AI assistants through MCP and to code through a REST API, with the source and citation attached. Ask your assistant:

Rank Counties in Massachusetts by population density using official data, and cite the source.
rank_places {"indicator":"population_density","level":"province","within":"Massachusetts","limit":10}
GET https://invokely.ai/api/v1/rank?indicator=population_density&level=province&within=Massachusetts&limit=10

Connect Claude, ChatGPT or Cursor in one step. The trial answers 25 calls a day without an account.

Questions

Which county has the highest population density?

Suffolk County, with 5,244.8 inhabitants per km² in 2020, according to the U.S. Census Bureau.

Which county has the lowest population density?

Franklin County, with 39.2 inhabitants per km² in 2020.

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