| | Castroville, TX | Hutto, TX | United States |
| Population | 2,939 | 26,971 | 329,725,481 |
| Female Population | 56.0% | 51.6% | 50.5% |
| Male Population | 44.0% | 48.4% | 49.5% |
| Median Age | 38.5 | 34.9 | 38.4 |
| space3 | | | |
| Population - 2010 | 2,791 | 16,724 | 309,327,143 |
| Population - 2000 | 2,664 | 1,250 | 285,036,114 |
| Population - 1990 | 2,159 | 630 | 251,960,433 |
| Pop. 2000 to Now | 20.1% | 2,299.0% | 15.6% |
| Pop. 1990 to Now | 48.2% | 4,659.8% | 30.8% |
| space4 | | | |
| Population Density | 1,071.9 | 3,219.3 | 93.4 |
| Land Area | 2.7 | 8.4 | 3,531,905.4 |
| Water Area | 0.0 | 0.0 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Castroville, TX | Hutto, TX | United States |
| Age 0 to 4 | 6.1% | 5.9% | 5.9% |
| Age 5 to 9 | 6.0% | 7.3% | 6.1% |
| Age 10 to 14 | 6.7% | 7.7% | 6.6% |
| Age 15 to 17 | 4.4% | 5.2% | 3.9% |
| Age 18 to 20 | 3.0% | 4.0% | 4.0% |
| Age 21 to 24 | 7.8% | 3.8% | 5.2% |
| Age 25 to 34 | 12.2% | 16.5% | 13.8% |
| Age 35 to 44 | 6.8% | 22.2% | 12.9% |
| Age 45 to 54 | 14.0% | 13.8% | 12.6% |
| Age 55 to 59 | 7.4% | 4.9% | 6.7% |
| Age 60 to 64 | 6.3% | 3.6% | 6.3% |
| Age 65 to 74 | 7.9% | 3.3% | 9.6% |
| Age 75 to 84 | 8.3% | 1.7% | 4.5% |
| Age 85 and over | 3.0% | 0.3% | 1.9% |
| space1 | | | |
| Race | | | |
| | Castroville, TX | Hutto, TX | United States |
| White | 47.1% | 49.2% | 59.4% |
| Black | 0.6% | 12.2% | 12.2% |
| Asian | 1.5% | 0.8% | 5.6% |
| Native American | 0.0% | 0.0% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.0% | 0.4% | 0.4% |
| Two or More Races | 3.8% | 3.6% | 3.2% |
| Hispanic | 47.1% | 33.8% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Castroville, TX | Hutto, TX | United States |
| Married Population | 56.6% | 58.1% | 49.8% |
| Currently Married | 55.0% | 56.0% | 48.0% |
| Married but Separated | 1.6% | 2.1% | 1.8% |
| Single Population | 43.4% | 41.9% | 50.2% |
| Never Married | 26.1% | 28.8% | 33.8% |
| Divorced | 10.2% | 11.1% | 10.8% |
| Widowed | 7.0% | 2.0% | 5.6% |
| space5 | | | |
| Household Size | 2.70 | 2.99 | 2.60 |
| Households | 1,057 | 9,027 | 124,010,992 |
| Family Households | 794 | 7,109 | 80,755,759 |
| Married couple, w/children | 27.8% | 45.8% | 30.5% |
| Married couple, no children | 46.3% | 30.3% | 42.9% |
| Non Family Households | 263 | 1,918 | 43,255,233 |
| Single householder, w/children | 12.0% | 14.9% | 15.8% |
| Single householder, no children | 13.9% | 9.1% | 10.8% |