| | Frenchtown, NJ | Pennington, NJ | United States |
| Population | 1,673 | 2,777 | 329,725,481 |
| Female Population | 55.7% | 52.9% | 50.5% |
| Male Population | 44.4% | 47.1% | 49.5% |
| Median Age | 40.4 | 47.8 | 38.4 |
| space3 | | | |
| Population - 2010 | 1,393 | 2,559 | 309,327,143 |
| Population - 2000 | 1,488 | 2,696 | 285,036,114 |
| Population - 1990 | 1,528 | 2,537 | 251,960,433 |
| Pop. 2000 to Now | -9.3% | -3.3% | 15.6% |
| Pop. 1990 to Now | -11.7% | 2.8% | 30.8% |
| space4 | | | |
| Population Density | 1,483.2 | 2,889.7 | 93.4 |
| Land Area | 1.1 | 1.0 | 3,531,905.4 |
| Water Area | 0.1 | 0.0 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Frenchtown, NJ | Pennington, NJ | United States |
| Age 0 to 4 | 5.3% | 6.0% | 5.9% |
| Age 5 to 9 | 9.0% | 5.9% | 6.1% |
| Age 10 to 14 | 9.5% | 6.2% | 6.6% |
| Age 15 to 17 | 6.5% | 5.0% | 3.9% |
| Age 18 to 20 | 2.6% | 1.0% | 4.0% |
| Age 21 to 24 | 2.3% | 4.0% | 5.2% |
| Age 25 to 34 | 7.4% | 6.7% | 13.8% |
| Age 35 to 44 | 14.1% | 10.7% | 12.9% |
| Age 45 to 54 | 20.2% | 15.5% | 12.6% |
| Age 55 to 59 | 5.4% | 5.8% | 6.7% |
| Age 60 to 64 | 4.7% | 8.4% | 6.3% |
| Age 65 to 74 | 7.3% | 15.3% | 9.6% |
| Age 75 to 84 | 4.8% | 4.6% | 4.5% |
| Age 85 and over | 1.0% | 5.0% | 1.9% |
| space1 | | | |
| Race | | | |
| | Frenchtown, NJ | Pennington, NJ | United States |
| White | 86.2% | 85.2% | 59.4% |
| Black | 0.4% | 1.6% | 12.2% |
| Asian | 3.9% | 9.5% | 5.6% |
| Native American | 0.0% | 0.0% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.8% | 0.4% | 0.4% |
| Two or More Races | 4.0% | 1.8% | 3.2% |
| Hispanic | 4.7% | 1.4% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Frenchtown, NJ | Pennington, NJ | United States |
| Married Population | 48.4% | 67.2% | 49.8% |
| Currently Married | 46.0% | 65.5% | 48.0% |
| Married but Separated | 2.4% | 1.7% | 1.8% |
| Single Population | 51.6% | 32.8% | 50.2% |
| Never Married | 33.9% | 20.6% | 33.8% |
| Divorced | 13.6% | 3.6% | 10.8% |
| Widowed | 4.2% | 8.6% | 5.6% |
| space5 | | | |
| Household Size | 2.51 | 2.38 | 2.60 |
| Households | 660 | 1,134 | 124,010,992 |
| Family Households | 433 | 811 | 80,755,759 |
| Married couple, w/children | 33.5% | 34.5% | 30.5% |
| Married couple, no children | 31.6% | 52.2% | 42.9% |
| Non Family Households | 227 | 323 | 43,255,233 |
| Single householder, w/children | 30.3% | 10.2% | 15.8% |
| Single householder, no children | 4.6% | 3.1% | 10.8% |