| | Rockwood, PA | Grantsville, MD | United States |
| Population | 809 | 752 | 329,725,481 |
| Female Population | 50.1% | 61.6% | 50.5% |
| Male Population | 49.9% | 38.4% | 49.5% |
| Median Age | 46.1 | 51.3 | 38.4 |
| space3 | | | |
| Population - 2010 | 889 | 896 | 309,327,143 |
| Population - 2000 | 954 | 619 | 285,036,114 |
| Population - 1990 | 1,014 | 505 | 251,960,433 |
| Pop. 2000 to Now | -14.6% | 39.7% | 15.6% |
| Pop. 1990 to Now | -19.6% | 71.3% | 30.8% |
| space4 | | | |
| Population Density | 2,422.2 | 725.2 | 93.4 |
| Land Area | 0.3 | 1.0 | 3,531,905.4 |
| Water Area | 0.0 | 0.0 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Rockwood, PA | Grantsville, MD | United States |
| Age 0 to 4 | 4.0% | 0.8% | 5.9% |
| Age 5 to 9 | 8.2% | 6.1% | 6.1% |
| Age 10 to 14 | 5.9% | 10.2% | 6.6% |
| Age 15 to 17 | 5.2% | 2.0% | 3.9% |
| Age 18 to 20 | 2.8% | 1.6% | 4.0% |
| Age 21 to 24 | 2.3% | 1.7% | 5.2% |
| Age 25 to 34 | 8.7% | 6.9% | 13.8% |
| Age 35 to 44 | 12.9% | 10.6% | 12.9% |
| Age 45 to 54 | 13.7% | 14.8% | 12.6% |
| Age 55 to 59 | 5.3% | 4.8% | 6.7% |
| Age 60 to 64 | 5.8% | 3.3% | 6.3% |
| Age 65 to 74 | 13.1% | 12.2% | 9.6% |
| Age 75 to 84 | 4.2% | 17.2% | 4.5% |
| Age 85 and over | 7.9% | 7.7% | 1.9% |
| space1 | | | |
| Race | | | |
| | Rockwood, PA | Grantsville, MD | United States |
| White | 96.9% | 98.7% | 59.4% |
| Black | 0.0% | 0.0% | 12.2% |
| Asian | 0.2% | 0.8% | 5.6% |
| Native American | 0.0% | 0.3% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.0% | 0.0% | 0.4% |
| Two or More Races | 1.5% | 0.0% | 3.2% |
| Hispanic | 1.4% | 0.3% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Rockwood, PA | Grantsville, MD | United States |
| Married Population | 42.5% | 41.9% | 49.8% |
| Currently Married | 41.2% | 40.9% | 48.0% |
| Married but Separated | 1.4% | 1.0% | 1.8% |
| Single Population | 57.5% | 58.1% | 50.2% |
| Never Married | 26.7% | 21.5% | 33.8% |
| Divorced | 19.6% | 15.9% | 10.8% |
| Widowed | 11.2% | 20.7% | 5.6% |
| space5 | | | |
| Household Size | 2.26 | 1.94 | 2.60 |
| Households | 351 | 336 | 124,010,992 |
| Family Households | 171 | 151 | 80,755,759 |
| Married couple, w/children | 33.9% | 29.8% | 30.5% |
| Married couple, no children | 35.1% | 41.1% | 42.9% |
| Non Family Households | 180 | 185 | 43,255,233 |
| Single householder, w/children | 22.2% | 25.2% | 15.8% |
| Single householder, no children | 8.8% | 4.0% | 10.8% |