| | Penn Hills, PA | Elkin, NC | United States |
| Population | 41,132 | 4,051 | 329,725,481 |
| Female Population | 53.7% | 49.4% | 50.5% |
| Male Population | 46.3% | 50.6% | 49.5% |
| Median Age | 44 | 42.1 | 38.4 |
| space3 | | | |
| Population - 2010 | 42,383 | 4,028 | 309,327,143 |
| Population - 2000 | 46,809 | 4,109 | 285,036,114 |
| Population - 1990 | 51,479 | 3,790 | 251,960,433 |
| Pop. 2000 to Now | -13.4% | -2.6% | 15.6% |
| Pop. 1990 to Now | -21.3% | 5.6% | 30.8% |
| space4 | | | |
| Population Density | 2,151.5 | 598.6 | 93.4 |
| Land Area | 19.1 | 6.8 | 3,531,905.4 |
| Water Area | 0.2 | 0.1 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Penn Hills, PA | Elkin, NC | United States |
| Age 0 to 4 | 5.3% | 2.6% | 5.9% |
| Age 5 to 9 | 5.8% | 5.3% | 6.1% |
| Age 10 to 14 | 5.0% | 8.7% | 6.6% |
| Age 15 to 17 | 3.5% | 4.3% | 3.9% |
| Age 18 to 20 | 2.9% | 2.7% | 4.0% |
| Age 21 to 24 | 4.0% | 6.4% | 5.2% |
| Age 25 to 34 | 13.0% | 11.4% | 13.8% |
| Age 35 to 44 | 11.2% | 13.9% | 12.9% |
| Age 45 to 54 | 13.4% | 12.8% | 12.6% |
| Age 55 to 59 | 6.6% | 6.1% | 6.7% |
| Age 60 to 64 | 7.7% | 4.7% | 6.3% |
| Age 65 to 74 | 12.4% | 11.3% | 9.6% |
| Age 75 to 84 | 5.9% | 6.4% | 4.5% |
| Age 85 and over | 3.1% | 3.4% | 1.9% |
| space1 | | | |
| Race | | | |
| | Penn Hills, PA | Elkin, NC | United States |
| White | 53.5% | 71.2% | 59.4% |
| Black | 38.3% | 3.8% | 12.2% |
| Asian | 0.3% | 2.4% | 5.6% |
| Native American | 0.1% | 0.1% | 0.6% |
| Hawaiian, Pacific Islander | 0.2% | 0.2% | 0.2% |
| Other | 1.3% | 0.7% | 0.4% |
| Two or More Races | 5.0% | 1.0% | 3.2% |
| Hispanic | 1.4% | 20.6% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Penn Hills, PA | Elkin, NC | United States |
| Married Population | 44.7% | 47.0% | 49.8% |
| Currently Married | 42.7% | 45.5% | 48.0% |
| Married but Separated | 2.0% | 1.5% | 1.8% |
| Single Population | 55.3% | 53.0% | 50.2% |
| Never Married | 36.9% | 29.4% | 33.8% |
| Divorced | 11.5% | 16.0% | 10.8% |
| Widowed | 6.8% | 7.6% | 5.6% |
| space5 | | | |
| Household Size | 2.24 | 2.37 | 2.60 |
| Households | 18,302 | 1,631 | 124,010,992 |
| Family Households | 10,500 | 962 | 80,755,759 |
| Married couple, w/children | 22.2% | 36.7% | 30.5% |
| Married couple, no children | 45.3% | 41.2% | 42.9% |
| Non Family Households | 7,802 | 669 | 43,255,233 |
| Single householder, w/children | 20.9% | 16.6% | 15.8% |
| Single householder, no children | 11.6% | 5.5% | 10.8% |