New Jersey counties by area
Official, comparable measurements for 21 counties and county equivalents.
Understanding New Jersey’s county areas
The land-area range runs from Hudson County at 46.2 mi² to Burlington County at 799.3 mi². The largest has 17.3 times the land area of the smallest and accounts for 10.9% of the combined county land in New Jersey.
The median county-equivalent land area is 322 mi², below the national median of 604.5 mi². The median describes the middle of the county size distribution; it does not describe how people or development are distributed. A state with a few very large counties can have a much smaller median than its largest entry suggests.
Where water changes the picture
Cape May County has the most assigned water area, at 368.8 mi². It also has the highest water share, with water making up 59.5% of its total area. Water area and water percentage answer different questions: the first measures an amount, while the second measures the mix of land and water.
Across all 21 entries, water accounts for 15.6% of the combined total area. This is calculated from the summed land and water measurements, rather than averaging county percentages, which would give each small and large county equal weight.
Compare the largest and smallest county equivalents in New Jersey to see land, water, and total area on the same scale.
These calculations use the 2026 Census county records listed below. County-equivalent boundaries vary between states; area alone does not measure population, density, or usable land. See coverage and calculation rules.
Complete area table
Sorted from largest to smallest land area.
| # | County / equivalent | Land | Water | Water share |
|---|---|---|---|---|
| 1 | Burlington CountyGEOID 34005 | 799.3 mi² | 21.1 mi² | 2.6% |
| 2 | Ocean CountyGEOID 34029 | 628.3 mi² | 286.5 mi² | 31.3% |
| 3 | Atlantic CountyGEOID 34001 | 555.6 mi² | 116.3 mi² | 17.3% |
| 4 | Sussex CountyGEOID 34037 | 518.5 mi² | 16.9 mi² | 3.2% |
| 5 | Cumberland CountyGEOID 34011 | 483.4 mi² | 194.5 mi² | 28.7% |
| 6 | Monmouth CountyGEOID 34025 | 468.2 mi² | 193.2 mi² | 29.2% |
| 7 | Morris CountyGEOID 34027 | 461 mi² | 20.5 mi² | 4.3% |
| 8 | Hunterdon CountyGEOID 34019 | 427.8 mi² | 9.6 mi² | 2.2% |
| 9 | Warren CountyGEOID 34041 | 356.5 mi² | 6.1 mi² | 1.7% |
| 10 | Salem CountyGEOID 34033 | 331.9 mi² | 40.7 mi² | 10.9% |
| 11 | Gloucester CountyGEOID 34015 | 322 mi² | 14.7 mi² | 4.4% |
| 12 | Middlesex CountyGEOID 34023 | 309.3 mi² | 13.6 mi² | 4.2% |
| 13 | Somerset CountyGEOID 34035 | 301.9 mi² | 3.1 mi² | 1% |
| 14 | Cape May CountyGEOID 34009 | 251.5 mi² | 368.8 mi² | 59.5% |
| 15 | Bergen CountyGEOID 34003 | 232.8 mi² | 13.7 mi² | 5.5% |
| 16 | Mercer CountyGEOID 34021 | 224.5 mi² | 4.4 mi² | 1.9% |
| 17 | Camden CountyGEOID 34007 | 221.4 mi² | 6.1 mi² | 2.7% |
| 18 | Passaic CountyGEOID 34031 | 186.1 mi² | 12.4 mi² | 6.2% |
| 19 | Essex CountyGEOID 34013 | 126.1 mi² | 3.3 mi² | 2.6% |
| 20 | Union CountyGEOID 34039 | 102.8 mi² | 2.6 mi² | 2.5% |
| 21 | Hudson CountyGEOID 34017 | 46.2 mi² | 16.2 mi² | 25.9% |