Data / Rankings / Population density / Counties in New Jersey

Counties in New Jersey by population density

Hudson County had the highest population density of 21 counties in 2020, at 6,033.2 inhabitants per km². Salem County had the lowest, at 75.4 inhabitants per km². The median was 425.6 inhabitants per km² and the figure for New Jersey was 486.7 inhabitants per km². Source: the U.S. Census Bureau.

Highest6,033.2Hudson County
Lowest75.4Salem County
Median425.621 counties
New Jersey486.7History

All counties, 2020

CSVChart (SVG)

Hudson CountyHudson County: 6,033.2 inhabitants per km²6,033.2Essex CountyEssex County: 2,633.4 inhabitants per km²2,633.4Union CountyUnion County: 2,154.6 inhabitants per km²2,154.6Bergen CountyBergen County: 1,582 inhabitants per km²1,582Passaic CountyPassaic County: 1,085.2 inhabitants per km²1,085.2Middlesex CountyMiddlesex County: 1,075.1 inhabitants per km²1,075.1Camden CountyCamden County: 912.6 inhabitants per km²912.6Mercer CountyMercer County: 664.7 inhabitants per km²664.7Monmouth CountyMonmouth County: 529.7 inhabitants per km²529.7Somerset CountySomerset County: 440.6 inhabitants per km²440.6Morris CountyMorris County: 425.6 inhabitants per km²425.6Ocean CountyOcean County: 392.2 inhabitants per km²392.2Gloucester CountyGloucester County: 362.8 inhabitants per km²362.8Burlington CountyBurlington County: 223 inhabitants per km²223Atlantic CountyAtlantic County: 190.5 inhabitants per km²190.5Cape May CountyCape May County: 145.9 inhabitants per km²145.9Cumberland CountyCumberland County: 122.8 inhabitants per km²122.8Warren CountyWarren County: 118.5 inhabitants per km²118.5Hunterdon CountyHunterdon County: 116.2 inhabitants per km²116.2Sussex CountySussex County: 107.1 inhabitants per km²107.1Salem CountySalem County: 75.4 inhabitants per km²75.4
inhabitants per km². Source: Invokely calculation with data from U.S. Census Bureau. Retrieved 2026-10-09.

Full ranking

RankCounties2020
inhabitants per km²
1Hudson County6,033.2
2Essex County2,633.4
3Union County2,154.6
4Bergen County1,582
5Passaic County1,085.2
6Middlesex County1,075.1
7Camden County912.6
8Mercer County664.7
9Monmouth County529.7
10Somerset County440.6
11Morris County425.6
12Ocean County392.2
13Gloucester County362.8
14Burlington County223
15Atlantic County190.5
16Cape May County145.9
17Cumberland County122.8
18Warren County118.5
19Hunterdon County116.2
20Sussex County107.1
21Salem County75.4

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 New Jersey by population density using official data, and cite the source.
rank_places {"indicator":"population_density","level":"province","within":"New Jersey","limit":10}
GET https://invokely.ai/api/v1/rank?indicator=population_density&level=province&within=New%20Jersey&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?

Hudson County, with 6,033.2 inhabitants per km² in 2020, according to the U.S. Census Bureau.

Which county has the lowest population density?

Salem County, with 75.4 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 New Jersey: more rankings