| | Harrisburg, PA | Johnstown, PA | United States |
| Population | 49,969 | 18,647 | 329,725,481 |
| Female Population | 51.5% | 53.0% | 50.5% |
| Male Population | 48.5% | 47.0% | 49.5% |
| Median Age | 31.6 | 44.4 | 38.4 |
| space3 | | | |
| Population - 2010 | 49,513 | 20,944 | 309,327,143 |
| Population - 2000 | 48,950 | 23,906 | 285,036,114 |
| Population - 1990 | 52,376 | 28,134 | 251,960,433 |
| Pop. 2000 to Now | 0.8% | -20.8% | 15.6% |
| Pop. 1990 to Now | -5.8% | -32.7% | 30.8% |
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| Population Density | 6,154.6 | 3,164.3 | 93.4 |
| Land Area | 8.1 | 5.9 | 3,531,905.4 |
| Water Area | 3.7 | 0.2 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Harrisburg, PA | Johnstown, PA | United States |
| Age 0 to 4 | 8.6% | 6.2% | 5.9% |
| Age 5 to 9 | 8.1% | 7.3% | 6.1% |
| Age 10 to 14 | 8.6% | 6.4% | 6.6% |
| Age 15 to 17 | 3.6% | 3.4% | 3.9% |
| Age 18 to 20 | 3.4% | 2.9% | 4.0% |
| Age 21 to 24 | 5.7% | 3.1% | 5.2% |
| Age 25 to 34 | 17.4% | 11.3% | 13.8% |
| Age 35 to 44 | 11.1% | 9.9% | 12.9% |
| Age 45 to 54 | 11.2% | 13.4% | 12.6% |
| Age 55 to 59 | 6.7% | 7.0% | 6.7% |
| Age 60 to 64 | 4.8% | 9.0% | 6.3% |
| Age 65 to 74 | 6.5% | 11.7% | 9.6% |
| Age 75 to 84 | 3.4% | 5.4% | 4.5% |
| Age 85 and over | 0.9% | 2.9% | 1.9% |
| space1 | | | |
| Race | | | |
| | Harrisburg, PA | Johnstown, PA | United States |
| White | 24.4% | 72.1% | 59.4% |
| Black | 44.0% | 16.2% | 12.2% |
| Asian | 2.6% | 0.4% | 5.6% |
| Native American | 0.2% | 0.0% | 0.6% |
| Hawaiian, Pacific Islander | 0.1% | 0.0% | 0.2% |
| Other | 0.4% | 1.1% | 0.4% |
| Two or More Races | 3.3% | 5.6% | 3.2% |
| Hispanic | 25.1% | 4.6% | 18.4% |
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| Marriage & Family | | | |
| | Harrisburg, PA | Johnstown, PA | United States |
| Married Population | 31.4% | 35.5% | 49.8% |
| Currently Married | 27.3% | 31.5% | 48.0% |
| Married but Separated | 4.2% | 4.0% | 1.8% |
| Single Population | 68.6% | 64.5% | 50.2% |
| Never Married | 49.4% | 40.8% | 33.8% |
| Divorced | 13.0% | 15.3% | 10.8% |
| Widowed | 6.1% | 8.4% | 5.6% |
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| Household Size | 2.33 | 2.06 | 2.60 |
| Households | 20,953 | 8,991 | 124,010,992 |
| Family Households | 10,507 | 4,208 | 80,755,759 |
| Married couple, w/children | 15.0% | 12.6% | 30.5% |
| Married couple, no children | 26.1% | 36.8% | 42.9% |
| Non Family Households | 10,446 | 4,783 | 43,255,233 |
| Single householder, w/children | 40.0% | 32.5% | 15.8% |
| Single householder, no children | 18.9% | 18.0% | 10.8% |