| | Seguin, TX | Norman, OK | United States |
| Population | 29,293 | 125,745 | 329,725,481 |
| Female Population | 52.7% | 50.3% | 50.5% |
| Male Population | 47.3% | 49.7% | 49.5% |
| Median Age | 36.4 | 31 | 38.4 |
| space3 | | | |
| Population - 2010 | 25,696 | 111,372 | 309,327,143 |
| Population - 2000 | 22,011 | 95,694 | 285,036,114 |
| Population - 1990 | 18,853 | 80,071 | 251,960,433 |
| Pop. 2000 to Now | 37.1% | 31.4% | 15.6% |
| Pop. 1990 to Now | 60.0% | 57.1% | 30.8% |
| space4 | | | |
| Population Density | 791.8 | 703.2 | 93.4 |
| Land Area | 37.0 | 178.8 | 3,531,905.4 |
| Water Area | 0.2 | 10.6 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Seguin, TX | Norman, OK | United States |
| Age 0 to 4 | 5.4% | 4.6% | 5.9% |
| Age 5 to 9 | 7.6% | 5.2% | 6.1% |
| Age 10 to 14 | 5.9% | 5.8% | 6.6% |
| Age 15 to 17 | 3.3% | 3.5% | 3.9% |
| Age 18 to 20 | 6.3% | 9.9% | 4.0% |
| Age 21 to 24 | 5.8% | 11.6% | 5.2% |
| Age 25 to 34 | 13.9% | 14.6% | 13.8% |
| Age 35 to 44 | 12.7% | 12.8% | 12.9% |
| Age 45 to 54 | 10.5% | 9.4% | 12.6% |
| Age 55 to 59 | 6.6% | 5.2% | 6.7% |
| Age 60 to 64 | 5.4% | 4.7% | 6.3% |
| Age 65 to 74 | 8.9% | 7.7% | 9.6% |
| Age 75 to 84 | 5.4% | 3.6% | 4.5% |
| Age 85 and over | 2.4% | 1.5% | 1.9% |
| space1 | | | |
| Race | | | |
| | Seguin, TX | Norman, OK | United States |
| White | 35.5% | 70.5% | 59.4% |
| Black | 6.0% | 4.6% | 12.2% |
| Asian | 1.4% | 4.3% | 5.6% |
| Native American | 0.1% | 3.8% | 0.6% |
| Hawaiian, Pacific Islander | 0.1% | 0.1% | 0.2% |
| Other | 0.2% | 0.4% | 0.4% |
| Two or More Races | 1.5% | 7.6% | 3.2% |
| Hispanic | 55.0% | 8.7% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Seguin, TX | Norman, OK | United States |
| Married Population | 44.2% | 43.3% | 49.8% |
| Currently Married | 41.2% | 41.9% | 48.0% |
| Married but Separated | 3.0% | 1.4% | 1.8% |
| Single Population | 55.8% | 56.7% | 50.2% |
| Never Married | 35.3% | 41.5% | 33.8% |
| Divorced | 13.3% | 11.2% | 10.8% |
| Widowed | 7.3% | 4.0% | 5.6% |
| space5 | | | |
| Household Size | 2.66 | 2.36 | 2.60 |
| Households | 10,499 | 50,129 | 124,010,992 |
| Family Households | 6,699 | 28,434 | 80,755,759 |
| Married couple, w/children | 28.0% | 33.2% | 30.5% |
| Married couple, no children | 36.8% | 39.9% | 42.9% |
| Non Family Households | 3,800 | 21,695 | 43,255,233 |
| Single householder, w/children | 21.6% | 16.8% | 15.8% |
| Single householder, no children | 13.6% | 10.1% | 10.8% |