| | Llano, TX | Whitney, TX | United States |
| Population | 3,301 | 2,097 | 329,725,481 |
| Female Population | 52.5% | 54.1% | 50.5% |
| Male Population | 47.5% | 45.9% | 49.5% |
| Median Age | 38.7 | 36.4 | 38.4 |
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| Population - 2010 | 3,251 | 2,086 | 309,327,143 |
| Population - 2000 | 3,325 | 1,833 | 285,036,114 |
| Population - 1990 | 2,962 | 1,626 | 251,960,433 |
| Pop. 2000 to Now | 5.5% | 17.0% | 15.6% |
| Pop. 1990 to Now | 18.4% | 31.9% | 30.8% |
| space4 | | | |
| Population Density | 626.5 | 1,127.4 | 93.4 |
| Land Area | 5.3 | 1.9 | 3,531,905.4 |
| Water Area | 0.3 | 0.0 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Llano, TX | Whitney, TX | United States |
| Age 0 to 4 | 8.7% | 7.3% | 5.9% |
| Age 5 to 9 | 5.2% | 8.3% | 6.1% |
| Age 10 to 14 | 4.8% | 9.1% | 6.6% |
| Age 15 to 17 | 4.4% | 4.9% | 3.9% |
| Age 18 to 20 | 4.5% | 1.9% | 4.0% |
| Age 21 to 24 | 6.2% | 5.0% | 5.2% |
| Age 25 to 34 | 12.3% | 12.4% | 13.8% |
| Age 35 to 44 | 8.3% | 10.7% | 12.9% |
| Age 45 to 54 | 11.5% | 7.5% | 12.6% |
| Age 55 to 59 | 4.0% | 6.1% | 6.7% |
| Age 60 to 64 | 8.3% | 4.7% | 6.3% |
| Age 65 to 74 | 13.2% | 9.3% | 9.6% |
| Age 75 to 84 | 7.1% | 7.7% | 4.5% |
| Age 85 and over | 1.3% | 4.9% | 1.9% |
| space1 | | | |
| Race | | | |
| | Llano, TX | Whitney, TX | United States |
| White | 78.0% | 68.1% | 59.4% |
| Black | 0.3% | 6.2% | 12.2% |
| Asian | 1.2% | 1.5% | 5.6% |
| Native American | 0.8% | 0.0% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.8% | 0.0% | 0.4% |
| Two or More Races | 1.2% | 2.7% | 3.2% |
| Hispanic | 17.7% | 21.5% | 18.4% |
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| Marriage & Family | | | |
| | Llano, TX | Whitney, TX | United States |
| Married Population | 47.5% | 38.8% | 49.8% |
| Currently Married | 46.0% | 37.4% | 48.0% |
| Married but Separated | 1.6% | 1.4% | 1.8% |
| Single Population | 52.5% | 61.2% | 50.2% |
| Never Married | 27.4% | 34.2% | 33.8% |
| Divorced | 15.7% | 14.5% | 10.8% |
| Widowed | 9.4% | 12.5% | 5.6% |
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| Household Size | 2.56 | 2.70 | 2.60 |
| Households | 1,250 | 727 | 124,010,992 |
| Family Households | 809 | 482 | 80,755,759 |
| Married couple, w/children | 22.5% | 17.2% | 30.5% |
| Married couple, no children | 50.4% | 34.9% | 42.9% |
| Non Family Households | 441 | 245 | 43,255,233 |
| Single householder, w/children | 20.0% | 38.2% | 15.8% |
| Single householder, no children | 7.0% | 9.8% | 10.8% |