| | Steelton, PA | Middletown, PA | United States |
| Population | 6,217 | 9,469 | 329,725,481 |
| Female Population | 55.4% | 49.6% | 50.5% |
| Male Population | 44.6% | 50.4% | 49.5% |
| Median Age | 33.3 | 34.3 | 38.4 |
| space3 | | | |
| Population - 2010 | 5,989 | 8,948 | 309,327,143 |
| Population - 2000 | 5,858 | 9,242 | 285,036,114 |
| Population - 1990 | 5,152 | 9,254 | 251,960,433 |
| Pop. 2000 to Now | 1.7% | 4.1% | 15.6% |
| Pop. 1990 to Now | 15.6% | 4.0% | 30.8% |
| space4 | | | |
| Population Density | 3,279.0 | 4,664.5 | 93.4 |
| Land Area | 1.9 | 2.0 | 3,531,905.4 |
| Water Area | 0.0 | 0.1 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Steelton, PA | Middletown, PA | United States |
| Age 0 to 4 | 4.8% | 6.4% | 5.9% |
| Age 5 to 9 | 5.0% | 5.6% | 6.1% |
| Age 10 to 14 | 11.5% | 4.7% | 6.6% |
| Age 15 to 17 | 6.0% | 3.2% | 3.9% |
| Age 18 to 20 | 7.9% | 4.0% | 4.0% |
| Age 21 to 24 | 4.0% | 7.5% | 5.2% |
| Age 25 to 34 | 12.8% | 20.2% | 13.8% |
| Age 35 to 44 | 13.6% | 9.6% | 12.9% |
| Age 45 to 54 | 13.8% | 10.0% | 12.6% |
| Age 55 to 59 | 4.1% | 8.0% | 6.7% |
| Age 60 to 64 | 4.8% | 5.5% | 6.3% |
| Age 65 to 74 | 6.0% | 8.3% | 9.6% |
| Age 75 to 84 | 4.6% | 4.1% | 4.5% |
| Age 85 and over | 1.0% | 3.1% | 1.9% |
| space1 | | | |
| Race | | | |
| | Steelton, PA | Middletown, PA | United States |
| White | 38.5% | 75.3% | 59.4% |
| Black | 38.3% | 8.7% | 12.2% |
| Asian | 0.0% | 5.4% | 5.6% |
| Native American | 0.0% | 0.1% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.0% | 0.3% | 0.4% |
| Two or More Races | 5.2% | 2.6% | 3.2% |
| Hispanic | 18.0% | 7.6% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Steelton, PA | Middletown, PA | United States |
| Married Population | 27.6% | 37.1% | 49.8% |
| Currently Married | 27.0% | 34.3% | 48.0% |
| Married but Separated | 0.6% | 2.8% | 1.8% |
| Single Population | 72.4% | 62.9% | 50.2% |
| Never Married | 51.1% | 40.6% | 33.8% |
| Divorced | 14.6% | 14.4% | 10.8% |
| Widowed | 6.6% | 7.9% | 5.6% |
| space5 | | | |
| Household Size | 2.75 | 2.18 | 2.60 |
| Households | 2,253 | 4,267 | 124,010,992 |
| Family Households | 1,548 | 2,103 | 80,755,759 |
| Married couple, w/children | 17.5% | 24.0% | 30.5% |
| Married couple, no children | 21.1% | 38.2% | 42.9% |
| Non Family Households | 705 | 2,164 | 43,255,233 |
| Single householder, w/children | 31.8% | 22.5% | 15.8% |
| Single householder, no children | 29.7% | 15.3% | 10.8% |