| | Harker Heights, TX | Fort Payne, AL | United States |
| Population | 32,320 | 14,730 | 329,725,481 |
| Female Population | 50.2% | 51.8% | 50.5% |
| Male Population | 49.9% | 48.2% | 49.5% |
| Median Age | 33.8 | 39.8 | 38.4 |
| space3 | | | |
| Population - 2010 | 26,978 | 14,069 | 309,327,143 |
| Population - 2000 | 17,308 | 12,938 | 285,036,114 |
| Population - 1990 | 12,841 | 11,838 | 251,960,433 |
| Pop. 2000 to Now | 91.1% | 8.5% | 15.6% |
| Pop. 1990 to Now | 157.5% | 18.6% | 30.8% |
| space4 | | | |
| Population Density | 2,065.8 | 262.2 | 93.4 |
| Land Area | 15.6 | 56.2 | 3,531,905.4 |
| Water Area | 0.1 | 0.4 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Harker Heights, TX | Fort Payne, AL | United States |
| Age 0 to 4 | 6.1% | 6.9% | 5.9% |
| Age 5 to 9 | 8.5% | 6.8% | 6.1% |
| Age 10 to 14 | 8.6% | 8.0% | 6.6% |
| Age 15 to 17 | 5.3% | 2.9% | 3.9% |
| Age 18 to 20 | 4.8% | 2.7% | 4.0% |
| Age 21 to 24 | 3.5% | 6.0% | 5.2% |
| Age 25 to 34 | 14.1% | 10.1% | 13.8% |
| Age 35 to 44 | 17.6% | 13.1% | 12.9% |
| Age 45 to 54 | 11.2% | 10.7% | 12.6% |
| Age 55 to 59 | 6.8% | 8.2% | 6.7% |
| Age 60 to 64 | 3.8% | 6.6% | 6.3% |
| Age 65 to 74 | 7.1% | 11.3% | 9.6% |
| Age 75 to 84 | 1.8% | 5.2% | 4.5% |
| Age 85 and over | 0.9% | 1.5% | 1.9% |
| space1 | | | |
| Race | | | |
| | Harker Heights, TX | Fort Payne, AL | United States |
| White | 44.2% | 76.1% | 59.4% |
| Black | 25.8% | 2.9% | 12.2% |
| Asian | 3.6% | 0.0% | 5.6% |
| Native American | 0.3% | 0.2% | 0.6% |
| Hawaiian, Pacific Islander | 0.5% | 0.0% | 0.2% |
| Other | 0.1% | 1.4% | 0.4% |
| Two or More Races | 6.0% | 1.5% | 3.2% |
| Hispanic | 19.5% | 17.9% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Harker Heights, TX | Fort Payne, AL | United States |
| Married Population | 50.2% | 52.3% | 49.8% |
| Currently Married | 48.1% | 48.8% | 48.0% |
| Married but Separated | 2.1% | 3.5% | 1.8% |
| Single Population | 49.8% | 47.7% | 50.2% |
| Never Married | 32.9% | 22.9% | 33.8% |
| Divorced | 13.1% | 18.3% | 10.8% |
| Widowed | 3.8% | 6.6% | 5.6% |
| space5 | | | |
| Household Size | 2.81 | 2.58 | 2.60 |
| Households | 11,426 | 5,536 | 124,010,992 |
| Family Households | 8,211 | 3,501 | 80,755,759 |
| Married couple, w/children | 34.0% | 32.6% | 30.5% |
| Married couple, no children | 31.7% | 41.7% | 42.9% |
| Non Family Households | 3,215 | 2,035 | 43,255,233 |
| Single householder, w/children | 26.0% | 15.2% | 15.8% |
| Single householder, no children | 8.3% | 10.4% | 10.8% |