| | Olyphant, PA | Fairmont, WV | United States |
| Population | 5,359 | 18,369 | 329,725,481 |
| Female Population | 54.1% | 51.3% | 50.5% |
| Male Population | 45.9% | 48.7% | 49.5% |
| Median Age | 41.7 | 34.4 | 38.4 |
| space3 | | | |
| Population - 2010 | 5,160 | 18,725 | 309,327,143 |
| Population - 2000 | 4,978 | 19,097 | 285,036,114 |
| Population - 1990 | 5,222 | 20,210 | 251,960,433 |
| Pop. 2000 to Now | 0.6% | -3.8% | 15.6% |
| Pop. 1990 to Now | -4.1% | -9.1% | 30.8% |
| space4 | | | |
| Population Density | 985.7 | 2,138.4 | 93.4 |
| Land Area | 5.4 | 8.6 | 3,531,905.4 |
| Water Area | 0.1 | 0.4 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Olyphant, PA | Fairmont, WV | United States |
| Age 0 to 4 | 2.5% | 6.4% | 5.9% |
| Age 5 to 9 | 5.0% | 4.9% | 6.1% |
| Age 10 to 14 | 8.9% | 4.3% | 6.6% |
| Age 15 to 17 | 7.0% | 2.7% | 3.9% |
| Age 18 to 20 | 3.1% | 6.8% | 4.0% |
| Age 21 to 24 | 5.2% | 9.8% | 5.2% |
| Age 25 to 34 | 8.1% | 15.9% | 13.8% |
| Age 35 to 44 | 15.5% | 11.8% | 12.9% |
| Age 45 to 54 | 16.4% | 9.7% | 12.6% |
| Age 55 to 59 | 5.7% | 5.9% | 6.7% |
| Age 60 to 64 | 5.0% | 4.9% | 6.3% |
| Age 65 to 74 | 9.1% | 10.2% | 9.6% |
| Age 75 to 84 | 4.4% | 4.2% | 4.5% |
| Age 85 and over | 4.0% | 2.5% | 1.9% |
| space1 | | | |
| Race | | | |
| | Olyphant, PA | Fairmont, WV | United States |
| White | 87.9% | 86.3% | 59.4% |
| Black | 0.0% | 6.5% | 12.2% |
| Asian | 0.2% | 0.6% | 5.6% |
| Native American | 0.0% | 0.2% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.0% | 1.2% | 0.4% |
| Two or More Races | 1.5% | 3.8% | 3.2% |
| Hispanic | 10.4% | 1.4% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Olyphant, PA | Fairmont, WV | United States |
| Married Population | 42.7% | 41.0% | 49.8% |
| Currently Married | 41.7% | 39.8% | 48.0% |
| Married but Separated | 0.9% | 1.2% | 1.8% |
| Single Population | 57.4% | 59.0% | 50.2% |
| Never Married | 39.4% | 40.1% | 33.8% |
| Divorced | 10.4% | 12.3% | 10.8% |
| Widowed | 7.5% | 6.6% | 5.6% |
| space5 | | | |
| Household Size | 2.36 | 2.21 | 2.60 |
| Households | 2,267 | 7,903 | 124,010,992 |
| Family Households | 1,483 | 4,273 | 80,755,759 |
| Married couple, w/children | 18.3% | 26.6% | 30.5% |
| Married couple, no children | 39.1% | 41.9% | 42.9% |
| Non Family Households | 784 | 3,630 | 43,255,233 |
| Single householder, w/children | 28.6% | 20.4% | 15.8% |
| Single householder, no children | 14.0% | 11.1% | 10.8% |