| | Grand Prairie, TX | Duncanville, TX | United States |
| Population | 195,992 | 40,575 | 329,725,481 |
| Female Population | 51.1% | 52.0% | 50.5% |
| Male Population | 48.9% | 48.0% | 49.5% |
| Median Age | 33.8 | 37.4 | 38.4 |
| space3 | | | |
| Population - 2010 | 175,940 | 38,617 | 309,327,143 |
| Population - 2000 | 127,427 | 36,081 | 285,036,114 |
| Population - 1990 | 99,616 | 35,748 | 251,960,433 |
| Pop. 2000 to Now | 53.2% | 5.8% | 15.6% |
| Pop. 1990 to Now | 96.0% | 6.8% | 30.8% |
| space4 | | | |
| Population Density | 2,709.5 | 3,622.1 | 93.4 |
| Land Area | 72.3 | 11.2 | 3,531,905.4 |
| Water Area | 8.9 | 0.0 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Grand Prairie, TX | Duncanville, TX | United States |
| Age 0 to 4 | 6.6% | 6.5% | 5.9% |
| Age 5 to 9 | 8.0% | 6.4% | 6.1% |
| Age 10 to 14 | 8.5% | 9.0% | 6.6% |
| Age 15 to 17 | 5.3% | 4.8% | 3.9% |
| Age 18 to 20 | 4.1% | 4.9% | 4.0% |
| Age 21 to 24 | 5.2% | 3.6% | 5.2% |
| Age 25 to 34 | 13.9% | 11.2% | 13.8% |
| Age 35 to 44 | 14.3% | 13.1% | 12.9% |
| Age 45 to 54 | 12.9% | 11.3% | 12.6% |
| Age 55 to 59 | 5.9% | 6.1% | 6.7% |
| Age 60 to 64 | 5.2% | 7.2% | 6.3% |
| Age 65 to 74 | 6.7% | 10.3% | 9.6% |
| Age 75 to 84 | 2.0% | 3.9% | 4.5% |
| Age 85 and over | 1.3% | 1.6% | 1.9% |
| space1 | | | |
| Race | | | |
| | Grand Prairie, TX | Duncanville, TX | United States |
| White | 21.1% | 23.4% | 59.4% |
| Black | 22.6% | 31.0% | 12.2% |
| Asian | 6.9% | 1.6% | 5.6% |
| Native American | 0.2% | 0.2% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.3% | 0.2% | 0.4% |
| Two or More Races | 2.2% | 1.1% | 3.2% |
| Hispanic | 46.7% | 42.4% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Grand Prairie, TX | Duncanville, TX | United States |
| Married Population | 52.3% | 50.2% | 49.8% |
| Currently Married | 49.9% | 47.7% | 48.0% |
| Married but Separated | 2.4% | 2.5% | 1.8% |
| Single Population | 47.7% | 49.8% | 50.2% |
| Never Married | 34.3% | 33.3% | 33.8% |
| Divorced | 9.4% | 10.5% | 10.8% |
| Widowed | 4.0% | 6.0% | 5.6% |
| space5 | | | |
| Household Size | 3.05 | 2.90 | 2.60 |
| Households | 64,108 | 13,912 | 124,010,992 |
| Family Households | 47,337 | 10,114 | 80,755,759 |
| Married couple, w/children | 35.5% | 28.0% | 30.5% |
| Married couple, no children | 35.6% | 39.0% | 42.9% |
| Non Family Households | 16,771 | 3,798 | 43,255,233 |
| Single householder, w/children | 19.1% | 19.8% | 15.8% |
| Single householder, no children | 9.9% | 13.2% | 10.8% |