Counties in New Jersey by population density
Hudson County had the highest population density of 21 counties in 2021, at 5,877.6 inhabitants per km². Salem County had the lowest, at 75.6 inhabitants per km². The median was 427.3 inhabitants per km² and the figure for New Jersey was 486.4 inhabitants per km². Source: the U.S. Census Bureau.
All counties, 2021
Full ranking
| Rank | Counties | 2021 | Change on 2020 |
|---|---|---|---|
| 1 | Hudson County | 5,877.6 | -2.6% |
| 2 | Essex County | 2,616.7 | -0.6% |
| 3 | Union County | 2,151 | -0.2% |
| 4 | Bergen County | 1,584.5 | +0.2% |
| 5 | Middlesex County | 1,076 | +0.1% |
| 6 | Passaic County | 1,074.8 | -1% |
| 7 | Camden County | 914.6 | +0.2% |
| 8 | Mercer County | 657.3 | -1.1% |
| 9 | Monmouth County | 532.6 | +0.5% |
| 10 | Somerset County | 442.6 | +0.5% |
| 11 | Morris County | 427.3 | +0.4% |
| 12 | Ocean County | 399 | +1.8% |
| 13 | Gloucester County | 365.3 | +0.7% |
| 14 | Burlington County | 224.4 | +0.6% |
| 15 | Atlantic County | 191 | +0.3% |
| 16 | Cape May County | 146.9 | +0.7% |
| 17 | Cumberland County | 121.5 | -1% |
| 18 | Warren County | 119.7 | +1% |
| 19 | Hunterdon County | 117 | +0.7% |
| 20 | Sussex County | 108.5 | +1.3% |
| 21 | Salem County | 75.6 | +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.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=10Questions
Which county has the highest population density?
Hudson County, with 5,877.6 inhabitants per km² in 2021, according to the U.S. Census Bureau.
Which county has the lowest population density?
Salem County, with 75.6 inhabitants per km² 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, 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
- Countries
- EU countries
- US states
- EU regions (NUTS 2)
- US counties
- Autonomous communities of Spain
- Provinces of Spain
- Municipalities of Spain
- Regions of Germany (NUTS 2)
- Regions of France (NUTS 2)
- Regions of Italy (NUTS 2)
- Regions of Poland (NUTS 2)
Counties in New Jersey: more rankings
- Asian population share
- Bachelor's degree or higher, population 25 and over
- Live births, July to June
- Black or African American population share
- Crude birth rate, July to June
- Crude death rate, July to June
- Deaths, July to June
- Foreign-born population share
- Real GDP growth
- GDP per capita, US dollars
- Gross domestic product (GDP), US dollars
- Hispanic or Latino population share
- Homeownership rate (US, housing units)
- Median age
- Median gross rent (monthly)
- Median home value