| | North Bellmore, NY | West Chester, PA | United States |
| Population | 21,535 | 18,592 | 329,725,481 |
| Female Population | 48.5% | 52.4% | 50.5% |
| Male Population | 51.5% | 47.6% | 49.5% |
| Median Age | 41.6 | 24.6 | 38.4 |
| space3 | | | |
| Population - 2010 | 19,575 | 18,472 | 309,327,143 |
| Population - 2000 | 20,079 | 17,861 | 285,036,114 |
| Population - 1990 | 19,707 | 18,041 | 251,960,433 |
| Pop. 2000 to Now | -0.7% | 12.2% | 15.6% |
| Pop. 1990 to Now | 1.2% | 11.1% | 30.8% |
| space4 | | | |
| Population Density | 8,219.5 | 10,071.5 | 93.4 |
| Land Area | 2.6 | 1.8 | 3,531,905.4 |
| Water Area | 0.0 | 0.0 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | North Bellmore, NY | West Chester, PA | United States |
| Age 0 to 4 | 4.1% | 2.9% | 5.9% |
| Age 5 to 9 | 7.4% | 2.6% | 6.1% |
| Age 10 to 14 | 8.0% | 2.7% | 6.6% |
| Age 15 to 17 | 3.4% | 2.1% | 3.9% |
| Age 18 to 20 | 2.0% | 24.7% | 4.0% |
| Age 21 to 24 | 4.4% | 16.5% | 5.2% |
| Age 25 to 34 | 13.0% | 18.8% | 13.8% |
| Age 35 to 44 | 12.4% | 7.6% | 12.9% |
| Age 45 to 54 | 13.1% | 7.3% | 12.6% |
| Age 55 to 59 | 8.3% | 3.4% | 6.7% |
| Age 60 to 64 | 8.6% | 2.7% | 6.3% |
| Age 65 to 74 | 9.7% | 5.8% | 9.6% |
| Age 75 to 84 | 3.9% | 1.9% | 4.5% |
| Age 85 and over | 1.8% | 0.9% | 1.9% |
| space1 | | | |
| Race | | | |
| | North Bellmore, NY | West Chester, PA | United States |
| White | 76.5% | 71.5% | 59.4% |
| Black | 2.9% | 12.1% | 12.2% |
| Asian | 5.4% | 1.7% | 5.6% |
| Native American | 0.0% | 0.0% | 0.6% |
| Hawaiian, Pacific Islander | 0.2% | 0.0% | 0.2% |
| Other | 0.0% | 0.1% | 0.4% |
| Two or More Races | 3.5% | 2.4% | 3.2% |
| Hispanic | 11.4% | 12.4% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | North Bellmore, NY | West Chester, PA | United States |
| Married Population | 62.4% | 21.1% | 49.8% |
| Currently Married | 61.7% | 19.6% | 48.0% |
| Married but Separated | 0.7% | 1.5% | 1.8% |
| Single Population | 37.6% | 78.9% | 50.2% |
| Never Married | 28.8% | 67.4% | 33.8% |
| Divorced | 3.6% | 8.1% | 10.8% |
| Widowed | 5.1% | 3.4% | 5.6% |
| space5 | | | |
| Household Size | 3.24 | 2.18 | 2.60 |
| Households | 6,595 | 6,832 | 124,010,992 |
| Family Households | 5,625 | 2,394 | 80,755,759 |
| Married couple, w/children | 40.7% | 22.3% | 30.5% |
| Married couple, no children | 48.2% | 40.8% | 42.9% |
| Non Family Households | 970 | 4,438 | 43,255,233 |
| Single householder, w/children | 4.0% | 20.0% | 15.8% |
| Single householder, no children | 7.1% | 17.0% | 10.8% |