| | Stillwater, OK | Plano, TX | United States |
| Population | 48,055 | 282,181 | 329,725,481 |
| Female Population | 49.7% | 50.4% | 50.5% |
| Male Population | 50.3% | 49.6% | 49.5% |
| Median Age | 23.8 | 38.8 | 38.4 |
| space3 | | | |
| Population - 2010 | 45,761 | 261,240 | 309,327,143 |
| Population - 2000 | 39,065 | 222,030 | 285,036,114 |
| Population - 1990 | 36,676 | 128,713 | 251,960,433 |
| Pop. 2000 to Now | 28.8% | 31.2% | 15.6% |
| Pop. 1990 to Now | 37.2% | 126.3% | 30.8% |
| space4 | | | |
| Population Density | 1,627.0 | 3,937.3 | 93.4 |
| Land Area | 29.5 | 71.7 | 3,531,905.4 |
| Water Area | 0.5 | 0.4 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Stillwater, OK | Plano, TX | United States |
| Age 0 to 4 | 4.0% | 5.6% | 5.9% |
| Age 5 to 9 | 4.4% | 6.0% | 6.1% |
| Age 10 to 14 | 4.2% | 6.7% | 6.6% |
| Age 15 to 17 | 2.3% | 4.1% | 3.9% |
| Age 18 to 20 | 18.4% | 3.4% | 4.0% |
| Age 21 to 24 | 20.6% | 4.8% | 5.2% |
| Age 25 to 34 | 13.4% | 13.6% | 13.8% |
| Age 35 to 44 | 9.7% | 15.3% | 12.9% |
| Age 45 to 54 | 6.6% | 13.8% | 12.6% |
| Age 55 to 59 | 3.1% | 7.4% | 6.7% |
| Age 60 to 64 | 3.5% | 6.0% | 6.3% |
| Age 65 to 74 | 5.1% | 8.5% | 9.6% |
| Age 75 to 84 | 3.7% | 3.5% | 4.5% |
| Age 85 and over | 1.1% | 1.3% | 1.9% |
| space1 | | | |
| Race | | | |
| | Stillwater, OK | Plano, TX | United States |
| White | 74.4% | 49.8% | 59.4% |
| Black | 4.3% | 8.5% | 12.2% |
| Asian | 6.4% | 22.2% | 5.6% |
| Native American | 3.2% | 0.2% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.1% | 0.2% |
| Other | 0.0% | 0.5% | 0.4% |
| Two or More Races | 7.2% | 2.8% | 3.2% |
| Hispanic | 4.5% | 15.8% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Stillwater, OK | Plano, TX | United States |
| Married Population | 29.5% | 58.1% | 49.8% |
| Currently Married | 28.8% | 57.0% | 48.0% |
| Married but Separated | 0.7% | 1.1% | 1.8% |
| Single Population | 70.5% | 41.9% | 50.2% |
| Never Married | 58.9% | 28.3% | 33.8% |
| Divorced | 7.2% | 9.8% | 10.8% |
| Widowed | 4.4% | 3.9% | 5.6% |
| space5 | | | |
| Household Size | 2.20 | 2.66 | 2.60 |
| Households | 18,618 | 106,022 | 124,010,992 |
| Family Households | 7,924 | 75,244 | 80,755,759 |
| Married couple, w/children | 27.5% | 38.4% | 30.5% |
| Married couple, no children | 43.4% | 42.0% | 42.9% |
| Non Family Households | 10,694 | 30,778 | 43,255,233 |
| Single householder, w/children | 14.9% | 10.3% | 15.8% |
| Single householder, no children | 14.3% | 9.3% | 10.8% |