| | Selinsgrove, PA | Augusta, ME | United States |
| Population | 5,774 | 18,895 | 329,725,481 |
| Female Population | 51.0% | 52.0% | 50.5% |
| Male Population | 49.0% | 48.1% | 49.5% |
| Median Age | 29.3 | 45 | 38.4 |
| space3 | | | |
| Population - 2010 | 5,652 | 19,096 | 309,327,143 |
| Population - 2000 | 5,383 | 18,560 | 285,036,114 |
| Population - 1990 | 5,384 | 21,325 | 251,960,433 |
| Pop. 2000 to Now | 9.9% | 1.0% | 15.6% |
| Pop. 1990 to Now | 9.8% | -12.1% | 30.8% |
| space4 | | | |
| Population Density | 3,153.5 | 342.6 | 93.4 |
| Land Area | 1.8 | 55.1 | 3,531,905.4 |
| Water Area | 0.1 | 2.9 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Selinsgrove, PA | Augusta, ME | United States |
| Age 0 to 4 | 2.7% | 5.6% | 5.9% |
| Age 5 to 9 | 3.0% | 4.3% | 6.1% |
| Age 10 to 14 | 1.6% | 4.0% | 6.6% |
| Age 15 to 17 | 1.8% | 3.7% | 3.9% |
| Age 18 to 20 | 26.6% | 2.8% | 4.0% |
| Age 21 to 24 | 10.7% | 4.3% | 5.2% |
| Age 25 to 34 | 8.5% | 15.2% | 13.8% |
| Age 35 to 44 | 8.5% | 10.2% | 12.9% |
| Age 45 to 54 | 6.6% | 13.2% | 12.6% |
| Age 55 to 59 | 5.1% | 8.1% | 6.7% |
| Age 60 to 64 | 5.3% | 5.6% | 6.3% |
| Age 65 to 74 | 10.1% | 11.7% | 9.6% |
| Age 75 to 84 | 4.7% | 8.4% | 4.5% |
| Age 85 and over | 4.9% | 3.0% | 1.9% |
| space1 | | | |
| Race | | | |
| | Selinsgrove, PA | Augusta, ME | United States |
| White | 85.4% | 91.1% | 59.4% |
| Black | 4.8% | 1.2% | 12.2% |
| Asian | 1.3% | 0.9% | 5.6% |
| Native American | 0.1% | 0.9% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.0% | 0.1% | 0.4% |
| Two or More Races | 3.2% | 3.6% | 3.2% |
| Hispanic | 5.2% | 2.2% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Selinsgrove, PA | Augusta, ME | United States |
| Married Population | 31.1% | 33.3% | 49.8% |
| Currently Married | 29.1% | 32.6% | 48.0% |
| Married but Separated | 2.0% | 0.7% | 1.8% |
| Single Population | 68.9% | 66.7% | 50.2% |
| Never Married | 50.7% | 37.6% | 33.8% |
| Divorced | 9.3% | 21.4% | 10.8% |
| Widowed | 8.9% | 7.7% | 5.6% |
| space5 | | | |
| Household Size | 1.87 | 1.94 | 2.60 |
| Households | 1,927 | 9,310 | 124,010,992 |
| Family Households | 884 | 4,199 | 80,755,759 |
| Married couple, w/children | 21.6% | 19.9% | 30.5% |
| Married couple, no children | 55.9% | 40.3% | 42.9% |
| Non Family Households | 1,043 | 5,111 | 43,255,233 |
| Single householder, w/children | 10.0% | 29.0% | 15.8% |
| Single householder, no children | 12.6% | 10.8% | 10.8% |