Hunterdon County ranks as the 4th among the highest-income counties in the United States with a per capita income of $36,370. It ranks fourth among U.S. counties for household income according to the most recent U.S. Census. Hunterdon County's median household income was $93,342, behind only Fairfax County and Loudoun County, Virginia and Howard County, Maryland. As of 2005, Hunterdon had the third-highest median property tax of any county in the nation at $6,988, the highest in New Jersey. As of the Tax Foundation's rankings based on 2006 data, Hunterdon had taken the top spot for highest median property tax at $7,999.
As of the census of 2000, there were 121,989 people, 43,678 households, and 32,845 families residing in the county. The population density was 284 people per square mile (110/km²). There were 45,032 housing units at an average density of 105 per square mile (40/km²). The racial makeup of the county was 93.91% White, 2.25% Black or African American, 0.14% Native American, 1.92% Asian, 0.03% Pacific Islander, 0.75% from other races, and 0.99% from two or more races. 2.76% of the population were Hispanic or Latino of any race. 18.7% were of Italian, 17.3% German, 14.5% Irish, 8.4% English, 7.3% Polish and 5.1% American ancestry according to Census 2000.
There were 43,678 households out of which 37.10% had children under the age of 18 living with them, 66.30% were married couples living together, 6.30% had a female householder with no husband present, and 24.80% were non-families. 20.00% of all households were made up of individuals and 6.50% had someone living alone who was 65 years of age or older. The average household size was 2.69 and the average family size was 3.14.
In the county the population was spread out with 25.70% under the age of 18, 5.80% from 18 to 24, 31.30% from 25 to 44, 27.10% from 45 to 64, and 10.00% who were 65 years of age or older. The median age was 39 years. For every 100 females there were 97.60 males. For every 100 females age 18 and over, there were 95.30 males.
Hunterdon County's median income for a household was $79,888, which makes it the fourth highest county in the country based on median household income. Median income for a family was $91,050 (these figures had risen to $97,793 and $113,280 respectively as of a 2007 estimate). Males had a median income of $61,888 versus $40,852 for females. The per capita income for the county was $36,370, which ranks as the thirteenth highest county in the country based on per capita income. About 1.60% of families and 2.60% of the population were below the poverty line, including 2.10% of those under age 18 and 4.20% of those age 65 or over. As of October 2007, Hunterdon County now has the highest median property taxes in the United States.