| | Hillsdale, NJ | New Milford, NJ | United States |
| Population | 10,166 | 16,912 | 329,725,481 |
| Female Population | 52.3% | 51.6% | 50.5% |
| Male Population | 47.7% | 48.4% | 49.5% |
| Median Age | 42.2 | 40.3 | 38.4 |
| space3 | | | |
| Population - 2010 | 10,193 | 16,363 | 309,327,143 |
| Population - 2000 | 10,087 | 16,400 | 285,036,114 |
| Population - 1990 | 9,750 | 15,990 | 251,960,433 |
| Pop. 2000 to Now | 1.7% | -0.5% | 15.6% |
| Pop. 1990 to Now | 5.2% | 2.1% | 30.8% |
| space4 | | | |
| Population Density | 3,503.1 | 7,407.8 | 93.4 |
| Land Area | 2.9 | 2.3 | 3,531,905.4 |
| Water Area | 0.0 | 0.0 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Hillsdale, NJ | New Milford, NJ | United States |
| Age 0 to 4 | 5.7% | 7.6% | 5.9% |
| Age 5 to 9 | 5.0% | 5.3% | 6.1% |
| Age 10 to 14 | 6.4% | 7.0% | 6.6% |
| Age 15 to 17 | 4.7% | 3.6% | 3.9% |
| Age 18 to 20 | 5.0% | 3.2% | 4.0% |
| Age 21 to 24 | 4.8% | 3.2% | 5.2% |
| Age 25 to 34 | 9.2% | 12.5% | 13.8% |
| Age 35 to 44 | 13.0% | 13.8% | 12.9% |
| Age 45 to 54 | 14.7% | 14.4% | 12.6% |
| Age 55 to 59 | 9.9% | 6.9% | 6.7% |
| Age 60 to 64 | 7.4% | 7.6% | 6.3% |
| Age 65 to 74 | 8.0% | 7.8% | 9.6% |
| Age 75 to 84 | 4.0% | 4.4% | 4.5% |
| Age 85 and over | 2.2% | 2.5% | 1.9% |
| space1 | | | |
| Race | | | |
| | Hillsdale, NJ | New Milford, NJ | United States |
| White | 79.7% | 54.0% | 59.4% |
| Black | 2.3% | 2.9% | 12.2% |
| Asian | 6.9% | 20.0% | 5.6% |
| Native American | 0.2% | 0.4% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.7% | 0.9% | 0.4% |
| Two or More Races | 1.9% | 3.3% | 3.2% |
| Hispanic | 8.4% | 18.5% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Hillsdale, NJ | New Milford, NJ | United States |
| Married Population | 59.6% | 58.3% | 49.8% |
| Currently Married | 58.7% | 57.3% | 48.0% |
| Married but Separated | 0.9% | 1.0% | 1.8% |
| Single Population | 40.4% | 41.7% | 50.2% |
| Never Married | 29.0% | 28.4% | 33.8% |
| Divorced | 5.2% | 7.6% | 10.8% |
| Widowed | 6.2% | 5.7% | 5.6% |
| space5 | | | |
| Household Size | 2.93 | 2.71 | 2.60 |
| Households | 3,457 | 6,167 | 124,010,992 |
| Family Households | 2,778 | 4,443 | 80,755,759 |
| Married couple, w/children | 40.1% | 39.5% | 30.5% |
| Married couple, no children | 46.8% | 40.6% | 42.9% |
| Non Family Households | 679 | 1,724 | 43,255,233 |
| Single householder, w/children | 2.8% | 10.1% | 15.8% |
| Single householder, no children | 10.3% | 9.8% | 10.8% |