Hunterdon County area

Hunterdon County, New Jersey covers 437.4 square miles: 427.8 square miles of land and 9.561 square miles of water. Its county seat is Flemington. An estimated 131,781 people lived there in 2025.

Official Census measurements · GEOID 340192026 Gazetteer · retrieved September 27, 2026
Land area427.8 mi²
Water area9.561 mi²
Population (2025)131,781
People per mi²308

County outline

Generalized outline of Hunterdon County, New Jersey
2025 Census cartographic boundary, fitted to this frame. County maps are not at a common scale. The 2026 area measurements below come from the separate Gazetteer release. Map source and limitations.

Where Hunterdon County is located

Hunterdon County highlighted on a map of all U.S. county equivalents. About the maps

Area breakdown

Land accounts for 97.8% of Hunterdon County’s measured area and water for 2.2%. Its combined area converts to 1,132.9 square kilometers or approximately 279,933 acres.

Green: land · blue: water

MeasurementSquare milesSquare kilometersAcres
Land427.8351,108.088273,814.4
Water9.56124.7636,119
Total437.3961,132.85279,933.4

How Hunterdon County compares

By original Census land area, Hunterdon County ranks #8 of 21 in New Jersey and #2374 of 3,222 nationally. National rankings include the 50 states, District of Columbia, and Puerto Rico.

Its land area is 1.329 times the New Jersey county-equivalent median of 322 square miles. It accounts for 5.8% of the combined county land area in the state.

See the complete New Jersey ranking · What counts as a county equivalent?

Population and density of Hunterdon County

The Census Bureau estimates that 131,781 people lived in Hunterdon County on July 1, 2025. That ranks #505 of 3,222 county equivalents nationally and #18 of 21 in New Jersey. Since the April 1, 2020 estimates base of 128,954, the population has grown by 2,827 (+2.2%), compared with +2.8% for New Jersey as a whole.

With 427.8 square miles of land, that is 308 people per square mile (119 per km²), placing Hunterdon County #499 nationally for density and #19 in New Jersey. The median county equivalent has 47 people per square mile; the New Jersey median is 1,137. Put another way, there are about 2.1 acres of land per resident.

Estimated population, 2020–2025 · line scaled to this county’s own range
July 1202020212022202320242025
Estimate128,773129,700129,859130,313131,097131,781
Change—+927+159+454+784+684

U.S. Census Bureau, Vintage 2025 population estimates. Estimates are revised each year and are not decennial census counts. Density divides the whole population by the whole county’s land area, so it describes an average, not how settlement is distributed within the county. Population sources and methods.

Cities and towns in Hunterdon County

Hunterdon County is divided into 26 municipalities and townships. In New Jersey, county subdivisions are local governments, and together they cover all of the county’s land and residents.

The most populous is Raritan township, with 25,281 residents (19.2% of the county). The largest by land is Readington township, at 47.6 mi², or 11.1% of the county’s land. The county seat, Flemington borough, has 4,856 residents. Among those with at least 1,000 residents in 2020, Frenchtown borough grew fastest since then (+9.2%).

County subdivisionPopulation 2025Since 2020Land mi²Share of county land
Raritan township25,281+7.8%37.58.8%
Readington township16,406+1.7%47.611.1%
Clinton township13,412−0.8%29.97%
Union township6,649+2.1%18.84.4%
Lebanon township6,229+0.6%31.47.3%
Tewksbury township5,925+1%31.67.4%
Holland township5,239+1.3%23.55.5%
Flemington boroughCounty seat4,856−0.6%1.0770.3%
Alexandria township4,811+0%27.56.4%
Delaware township4,597+0.8%36.78.6%
Lambertville city4,198+1.4%1.0840.3%
East Amwell township3,952+1.1%28.56.7%
Kingwood township3,864+2%358.2%
Bethlehem township3,774+0.9%20.74.8%
High Bridge borough3,603+1.8%2.3910.6%
Show the other 11 subdivisions
NamePopulation 2025Since 2020Land mi²
Franklin township3,288+0.6%23
West Amwell township3,037+1%21.6
Clinton town2,794+0.7%1.346
Glen Gardner borough1,690+0.9%1.548
Lebanon borough1,676+0.7%0.902
Frenchtown borough1,500+9.2%1.128
Hampton borough1,443+0.5%1.505
Milford borough1,224−0.5%1.182
Califon borough1,034+1.4%0.959
Bloomsbury borough802+0.8%0.932
Stockton borough4970%0.546

Population: U.S. Census Bureau Vintage 2025 subcounty estimates, counting only the part of each subdivision inside Hunterdon County. Land: 2026 Census Gazetteer. How communities are listed.

Metropolitan area

Hunterdon County is an outlying county of the New York-Newark-Jersey City, NY-NJ Metropolitan Statistical Area, in the Newark, NJ metropolitan division. Its 22 county equivalents have 20,112,448 residents on 6,139.7 square miles of land; Hunterdon County accounts for 7% of the land and 0.7% of the residents. By combined land it ranks #34 of 393 metropolitan areas, and #1 by population. It belongs to the New York-Newark, NY-NJ-CT-PA Combined Statistical Area.

County equivalentPopulation 2025Land mi²
Kings CountyNew York2,653,96369.4
Queens CountyNew York2,358,182108.7
New York CountyNew York1,664,86222.7
Suffolk CountyNew York1,546,090910.9
Bronx CountyNew York1,406,33242.2
Nassau CountyNew York1,398,939284.5
Westchester CountyNew York1,015,743430.8
Bergen County977,026232.8
Essex County896,379126.1
Middlesex County883,335309.3
Hudson County735,03346.2
Ocean County673,746628.3
Monmouth County651,035468.2
Union County601,863102.8
Passaic County531,624186.1
Morris County524,251461
Richmond CountyNew York501,29057.5
Rockland CountyNew York357,397173.7
Somerset County356,486301.9
Sussex County148,063518.5
Hunterdon County131,781427.8
Putnam CountyNew York99,028230.3

ZIP codes

26 ZIP Code Tabulation Areas have land in Hunterdon County; 20 of them have most of their land inside the county, and the others mainly cover neighboring areas.

0783007865078820797908525085300855108559085600880108802088040880908822088250882608827088290883308848088530885808867088760888708889

ZIP Code Tabulation Areas are the Census Bureau’s approximations of USPS ZIP Code service areas, from the 2020 Census relationship files. Lighter codes have less than half of their land in this county. Post-office-box and single-address ZIP Codes have no tabulation area.

Counties bordering Hunterdon County

Hunterdon County shares a land border with 5 county equivalents, including 1 in Pennsylvania. It has more land than 3 of them. The largest neighbor is Bucks County (604.4 mi²) and the smallest is Mercer County (224.5 mi²). Together with its neighbors, Hunterdon County forms a block of 2,376.2 mi² of land, of which it holds 18%.

Map of Hunterdon County and the 5 county equivalents that border it Bucks County, Pennsylvania: 604.4 mi² landWarren County, New Jersey: 356.5 mi² landSomerset County, New Jersey: 301.9 mi² landMercer County, New Jersey: 224.5 mi² landMorris County, New Jersey: 461 mi² land
Hunterdon County (dark) and its bordering county equivalents. Select a neighbor to open its profile. Drawn from the 2025 Census cartographic boundaries in an equal-area projection. How borders are determined.
Bordering county equivalentLand mi²Size vs. HunterdonCompare
Bucks CountyPennsylvania604.41.4× largerCompare
Morris County4611.1× largerCompare
Warren County356.51.2× smallerCompare
Somerset County301.91.4× smallerCompare
Mercer County224.51.9× smallerCompare

How big is Hunterdon County compared with U.S. states?

Hunterdon County has less land than any of the 50 states. Rhode Island, the smallest state by land area, has 1,033.9 mi², about 2.4 times as much. New Jersey’s county land could hold about 17 areas the size of Hunterdon County.

Land area: Hunterdon County and the closest-sized states
Hunterdon County427.8 mi²
Rhode Island1,033.9 mi²

Another way to picture it: the same land area would fill a square about 20.7 miles (33.3 km) on each side. Real county shapes are rarely square, so this is a scale reference rather than a width or driving distance.

State figures are the sums of each state’s county-equivalent land measurements in the same Census release, so states and counties are compared on the same basis. Published state totals can differ slightly because of rounding. Compare all states · Counties bigger than entire states.

What stands out about Hunterdon County?

Hunterdon County has more land than 848 of the other 3,221 county equivalents in the dataset.

Land area compared with the typical county equivalent
Hunterdon County427.8 mi²
New Jersey median322 mi²
National median604.5 mi²

A median is the middle county-equivalent measurement, not the average of the largest and smallest. All three bars use the same linear scale. Very small areas may appear as a thin sliver; the labels retain their values.

Does including water change its rank?

Using land plus water places Hunterdon County at #2,397 nationally by total area, 23 places farther from the top than its land rank. Other county equivalents gain more area when their water measurements are included.

Its water share is 2.2%, compared with a national county-equivalent median of 1.2% — 1 percentage points higher. This describes the statistical geography’s land/water mix, not flood exposure or developable land.

Closest positions in the national land ranking

These entries sit immediately beside Hunterdon County in the national ranking. They can be in different states and are not necessarily geographic neighbors.

Land rankCounty equivalentLand mi²Comparison
#2373Randolph County, Georgia428.2Compare
#2374Hunterdon County, New Jersey427.8This county
#2375Stanton County, Nebraska427.6Compare

Calculated from the same Census release as the area table. Total-area order uses original ALAND + AWATER; water shares and chart labels use published square miles. Calculation details.

Representative coordinates

The Census internal point is 40.565283, -74.911969. It represents a location inside the geography; it is not necessarily the centroid or the address of a courthouse.

Source and precision

U.S. Census Bureau, 2026 Gazetteer Files, Counties. Original ALAND: 1,108,086,255 m²; AWATER: 24,761,601 m². Rankings use ALAND; exact ties use ascending GEOID. Tables preserve Census-published square miles to three decimals, with conversions based on those values.

Download the official county source ZIP ↗ · Methodology

Common questions

How big is Hunterdon County?

Hunterdon County, New Jersey has 427.8 square miles (1,108.1 km²) of land and 9.561 square miles of water, for a total area of 437.4 square miles. It ranks #2374 of 3,222 U.S. county equivalents by land area.

Is Hunterdon County the largest county in New Jersey?

No. Hunterdon County ranks #8 of 21 in New Jersey by land area. The largest is Burlington County, with 799.3 square miles of land.

What counties border Hunterdon County?

Hunterdon County shares a land border with Bucks County, Pennsylvania, Warren County, Somerset County, Mercer County, and Morris County.

What is the population of Hunterdon County?

The Census Bureau estimates Hunterdon County had 131,781 residents on July 1, 2025, ranking #505 of 3,222 county equivalents. That is 308 people per square mile of land.

What is the county seat of Hunterdon County?

The county seat of Hunterdon County is Flemington.

What cities and towns are in Hunterdon County?

Hunterdon County has 26 county subdivisions (cities, towns and townships). The most populous five are Raritan township, Readington township, Clinton township, Union township, and Lebanon township.

Is Hunterdon County part of a metropolitan area?

Yes. It is an outlying county of the New York-Newark-Jersey City, NY-NJ Metropolitan Statistical Area, which has 22 county equivalents and 20,112,448 residents.

How many ZIP codes are in Hunterdon County?

26 ZIP Code Tabulation Areas have land in Hunterdon County, and 20 of them have most of their land inside the county. Census ZIP Code Tabulation Areas approximate USPS ZIP Code areas.

How does Hunterdon County compare with U.S. states?

It has less land than every state. Rhode Island, the smallest, has 2.4 times as much land.

How many acres of land are in Hunterdon County?

The land measurement converts to approximately 273,814 acres. Including water, total area is approximately 279,933 acres. One square mile equals 640 acres.

Why might another source show a different area?

Check whether it reports land or total area, its Census vintage, and its rounding. Our guide explains how to reconcile county area figures.

Can this establish a property boundary?

No. Statistical measurements and generalized maps do not establish property lines. Consult the relevant local surveying or land-records authority.

Cite this county

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