| | New Kensington, PA | Bellevue, PA | United States |
| Population | 12,222 | 8,287 | 329,725,481 |
| Female Population | 49.6% | 52.6% | 50.5% |
| Male Population | 50.4% | 47.4% | 49.5% |
| Median Age | 46.8 | 35.3 | 38.4 |
| space3 | | | |
| Population - 2010 | 13,105 | 8,352 | 309,327,143 |
| Population - 2000 | 14,701 | 8,770 | 285,036,114 |
| Population - 1990 | 15,894 | 9,126 | 251,960,433 |
| Pop. 2000 to Now | -17.1% | -9.0% | 15.6% |
| Pop. 1990 to Now | -23.3% | -12.6% | 30.8% |
| space4 | | | |
| Population Density | 3,095.0 | 8,213.1 | 93.4 |
| Land Area | 3.9 | 1.0 | 3,531,905.4 |
| Water Area | 0.3 | 0.1 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | New Kensington, PA | Bellevue, PA | United States |
| Age 0 to 4 | 4.4% | 5.4% | 5.9% |
| Age 5 to 9 | 4.9% | 4.0% | 6.1% |
| Age 10 to 14 | 6.0% | 3.3% | 6.6% |
| Age 15 to 17 | 2.9% | 2.1% | 3.9% |
| Age 18 to 20 | 4.5% | 0.5% | 4.0% |
| Age 21 to 24 | 3.5% | 5.7% | 5.2% |
| Age 25 to 34 | 10.0% | 28.8% | 13.8% |
| Age 35 to 44 | 11.3% | 14.3% | 12.9% |
| Age 45 to 54 | 11.3% | 8.3% | 12.6% |
| Age 55 to 59 | 8.0% | 5.7% | 6.7% |
| Age 60 to 64 | 11.6% | 6.6% | 6.3% |
| Age 65 to 74 | 13.3% | 9.4% | 9.6% |
| Age 75 to 84 | 5.7% | 3.4% | 4.5% |
| Age 85 and over | 2.6% | 2.5% | 1.9% |
| space1 | | | |
| Race | | | |
| | New Kensington, PA | Bellevue, PA | United States |
| White | 85.7% | 80.4% | 59.4% |
| Black | 8.4% | 12.0% | 12.2% |
| Asian | 2.2% | 0.3% | 5.6% |
| Native American | 0.0% | 0.0% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.2% | 0.2% | 0.4% |
| Two or More Races | 1.7% | 4.9% | 3.2% |
| Hispanic | 1.8% | 2.2% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | New Kensington, PA | Bellevue, PA | United States |
| Married Population | 43.4% | 36.8% | 49.8% |
| Currently Married | 42.2% | 35.5% | 48.0% |
| Married but Separated | 1.2% | 1.3% | 1.8% |
| Single Population | 56.6% | 63.2% | 50.2% |
| Never Married | 34.9% | 47.8% | 33.8% |
| Divorced | 13.9% | 9.5% | 10.8% |
| Widowed | 7.8% | 5.9% | 5.6% |
| space5 | | | |
| Household Size | 2.14 | 1.89 | 2.60 |
| Households | 5,714 | 4,337 | 124,010,992 |
| Family Households | 2,958 | 1,687 | 80,755,759 |
| Married couple, w/children | 21.0% | 28.4% | 30.5% |
| Married couple, no children | 49.4% | 44.8% | 42.9% |
| Non Family Households | 2,756 | 2,650 | 43,255,233 |
| Single householder, w/children | 22.4% | 13.0% | 15.8% |
| Single householder, no children | 7.3% | 13.8% | 10.8% |