| | Belle Vernon, PA | Keyser, WV | United States |
| Population | 783 | 4,916 | 329,725,481 |
| Female Population | 52.9% | 52.9% | 50.5% |
| Male Population | 47.1% | 47.1% | 49.5% |
| Median Age | 51.4 | 40.8 | 38.4 |
| space3 | | | |
| Population - 2010 | 1,088 | 5,411 | 309,327,143 |
| Population - 2000 | 1,211 | 5,303 | 285,036,114 |
| Population - 1990 | 1,213 | 5,870 | 251,960,433 |
| Pop. 2000 to Now | -15.4% | -8.3% | 15.6% |
| Pop. 1990 to Now | -15.6% | -17.2% | 30.8% |
| space4 | | | |
| Population Density | 3,132.0 | 2,489.1 | 93.4 |
| Land Area | 0.3 | 2.0 | 3,531,905.4 |
| Water Area | 0.1 | 0.0 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Belle Vernon, PA | Keyser, WV | United States |
| Age 0 to 4 | 4.3% | 0.0% | 5.9% |
| Age 5 to 9 | 0.0% | 4.3% | 6.1% |
| Age 10 to 14 | 3.3% | 9.7% | 6.6% |
| Age 15 to 17 | 1.0% | 1.8% | 3.9% |
| Age 18 to 20 | 4.5% | 9.8% | 4.0% |
| Age 21 to 24 | 1.3% | 0.9% | 5.2% |
| Age 25 to 34 | 20.3% | 18.6% | 13.8% |
| Age 35 to 44 | 10.1% | 12.1% | 12.9% |
| Age 45 to 54 | 7.0% | 12.2% | 12.6% |
| Age 55 to 59 | 6.8% | 1.3% | 6.7% |
| Age 60 to 64 | 10.3% | 7.0% | 6.3% |
| Age 65 to 74 | 14.7% | 15.8% | 9.6% |
| Age 75 to 84 | 11.1% | 5.1% | 4.5% |
| Age 85 and over | 5.2% | 1.5% | 1.9% |
| space1 | | | |
| Race | | | |
| | Belle Vernon, PA | Keyser, WV | United States |
| White | 91.3% | 88.3% | 59.4% |
| Black | 3.6% | 8.4% | 12.2% |
| Asian | 1.1% | 0.0% | 5.6% |
| Native American | 0.0% | 0.0% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.0% | 2.4% | 0.4% |
| Two or More Races | 3.7% | 0.8% | 3.2% |
| Hispanic | 0.3% | 0.1% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Belle Vernon, PA | Keyser, WV | United States |
| Married Population | 32.9% | 41.0% | 49.8% |
| Currently Married | 28.1% | 38.6% | 48.0% |
| Married but Separated | 4.8% | 2.4% | 1.8% |
| Single Population | 67.1% | 59.0% | 50.2% |
| Never Married | 30.8% | 37.5% | 33.8% |
| Divorced | 25.6% | 11.3% | 10.8% |
| Widowed | 10.7% | 10.2% | 5.6% |
| space5 | | | |
| Household Size | 1.58 | 2.13 | 2.60 |
| Households | 497 | 2,107 | 124,010,992 |
| Family Households | 167 | 964 | 80,755,759 |
| Married couple, w/children | 19.2% | 21.6% | 30.5% |
| Married couple, no children | 38.9% | 39.7% | 42.9% |
| Non Family Households | 330 | 1,143 | 43,255,233 |
| Single householder, w/children | 19.2% | 15.6% | 15.8% |
| Single householder, no children | 22.8% | 23.1% | 10.8% |