| | Belford, NJ | Atlantic Highlands, NJ | United States |
| Population | 2,027 | 4,414 | 329,725,481 |
| Female Population | 50.1% | 49.0% | 50.5% |
| Male Population | 49.9% | 51.0% | 49.5% |
| Median Age | 35.7 | 47.5 | 38.4 |
| space3 | | | |
| Population - 2010 | 1,396 | 4,378 | 309,327,143 |
| Population - 2000 | 1,340 | 4,705 | 285,036,114 |
| Population - 1990 | 1,755 | 4,629 | 251,960,433 |
| Pop. 2000 to Now | 28.9% | -7.3% | 15.6% |
| Pop. 1990 to Now | -1.6% | -5.8% | 30.8% |
| space4 | | | |
| Population Density | 1,610.0 | 3,492.1 | 93.4 |
| Land Area | 1.3 | 1.3 | 3,531,905.4 |
| Water Area | 0.0 | 3.3 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Belford, NJ | Atlantic Highlands, NJ | United States |
| Age 0 to 4 | 7.0% | 3.6% | 5.9% |
| Age 5 to 9 | 5.8% | 2.9% | 6.1% |
| Age 10 to 14 | 7.0% | 8.5% | 6.6% |
| Age 15 to 17 | 9.3% | 4.3% | 3.9% |
| Age 18 to 20 | 7.5% | 2.4% | 4.0% |
| Age 21 to 24 | 1.1% | 3.6% | 5.2% |
| Age 25 to 34 | 12.0% | 12.2% | 13.8% |
| Age 35 to 44 | 11.5% | 8.5% | 12.9% |
| Age 45 to 54 | 16.3% | 17.7% | 12.6% |
| Age 55 to 59 | 9.4% | 8.9% | 6.7% |
| Age 60 to 64 | 4.9% | 9.0% | 6.3% |
| Age 65 to 74 | 5.7% | 9.4% | 9.6% |
| Age 75 to 84 | 1.9% | 6.3% | 4.5% |
| Age 85 and over | 0.5% | 2.9% | 1.9% |
| space1 | | | |
| Race | | | |
| | Belford, NJ | Atlantic Highlands, NJ | United States |
| White | 83.3% | 91.0% | 59.4% |
| Black | 0.6% | 0.0% | 12.2% |
| Asian | 0.4% | 0.7% | 5.6% |
| Native American | 0.0% | 0.0% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.0% | 0.4% | 0.4% |
| Two or More Races | 4.3% | 1.0% | 3.2% |
| Hispanic | 11.3% | 6.8% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Belford, NJ | Atlantic Highlands, NJ | United States |
| Married Population | 56.9% | 50.7% | 49.8% |
| Currently Married | 56.2% | 49.6% | 48.0% |
| Married but Separated | 0.6% | 1.1% | 1.8% |
| Single Population | 43.1% | 49.3% | 50.2% |
| Never Married | 33.9% | 32.8% | 33.8% |
| Divorced | 7.1% | 9.3% | 10.8% |
| Widowed | 2.1% | 7.1% | 5.6% |
| space5 | | | |
| Household Size | 3.26 | 2.33 | 2.60 |
| Households | 621 | 1,895 | 124,010,992 |
| Family Households | 475 | 1,134 | 80,755,759 |
| Married couple, w/children | 52.4% | 31.4% | 30.5% |
| Married couple, no children | 37.3% | 48.9% | 42.9% |
| Non Family Households | 146 | 761 | 43,255,233 |
| Single householder, w/children | 2.3% | 9.6% | 15.8% |
| Single householder, no children | 8.0% | 10.1% | 10.8% |