| | Rosslyn Farms, PA | Carlisle, PA | United States |
| Population | 465 | 19,869 | 329,725,481 |
| Female Population | 59.8% | 51.6% | 50.5% |
| Male Population | 40.2% | 48.4% | 49.5% |
| Median Age | 52.5 | 34.9 | 38.4 |
| space3 | | | |
| Population - 2010 | 437 | 18,754 | 309,327,143 |
| Population - 2000 | 464 | 17,970 | 285,036,114 |
| Population - 1990 | 483 | 18,419 | 251,960,433 |
| Pop. 2000 to Now | -10.1% | 6.9% | 15.6% |
| Pop. 1990 to Now | -13.7% | 4.3% | 30.8% |
| space4 | | | |
| Population Density | 830.4 | 3,591.0 | 93.4 |
| Land Area | 0.6 | 5.5 | 3,531,905.4 |
| Water Area | 0.0 | 0.0 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Rosslyn Farms, PA | Carlisle, PA | United States |
| Age 0 to 4 | 4.9% | 6.7% | 5.9% |
| Age 5 to 9 | 5.6% | 4.6% | 6.1% |
| Age 10 to 14 | 6.0% | 4.9% | 6.6% |
| Age 15 to 17 | 6.0% | 3.5% | 3.9% |
| Age 18 to 20 | 0.4% | 9.7% | 4.0% |
| Age 21 to 24 | 2.2% | 6.8% | 5.2% |
| Age 25 to 34 | 4.9% | 13.8% | 13.8% |
| Age 35 to 44 | 11.8% | 10.5% | 12.9% |
| Age 45 to 54 | 9.9% | 10.1% | 12.6% |
| Age 55 to 59 | 5.6% | 6.9% | 6.7% |
| Age 60 to 64 | 5.8% | 5.2% | 6.3% |
| Age 65 to 74 | 12.7% | 10.4% | 9.6% |
| Age 75 to 84 | 4.9% | 4.5% | 4.5% |
| Age 85 and over | 19.1% | 2.4% | 1.9% |
| space1 | | | |
| Race | | | |
| | Rosslyn Farms, PA | Carlisle, PA | United States |
| White | 79.4% | 78.0% | 59.4% |
| Black | 0.2% | 8.4% | 12.2% |
| Asian | 0.6% | 2.6% | 5.6% |
| Native American | 0.0% | 0.0% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.0% | 0.4% | 0.4% |
| Two or More Races | 18.3% | 3.1% | 3.2% |
| Hispanic | 1.5% | 7.6% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Rosslyn Farms, PA | Carlisle, PA | United States |
| Married Population | 52.1% | 39.2% | 49.8% |
| Currently Married | 51.0% | 37.5% | 48.0% |
| Married but Separated | 1.0% | 1.7% | 1.8% |
| Single Population | 47.9% | 60.8% | 50.2% |
| Never Married | 18.3% | 42.6% | 33.8% |
| Divorced | 4.4% | 12.7% | 10.8% |
| Widowed | 25.3% | 5.5% | 5.6% |
| space5 | | | |
| Household Size | 1.99 | 2.13 | 2.60 |
| Households | 234 | 8,099 | 124,010,992 |
| Family Households | 105 | 4,167 | 80,755,759 |
| Married couple, w/children | 34.3% | 24.0% | 30.5% |
| Married couple, no children | 58.1% | 46.8% | 42.9% |
| Non Family Households | 129 | 3,932 | 43,255,233 |
| Single householder, w/children | 5.7% | 21.6% | 15.8% |
| Single householder, no children | 1.9% | 7.7% | 10.8% |