| | Sandia, TX | Robstown, TX | United States |
| Population | 382 | 10,372 | 329,725,481 |
| Female Population | 44.8% | 52.4% | 50.5% |
| Male Population | 55.2% | 47.6% | 49.5% |
| Median Age | 58 | 36.7 | 38.4 |
| space3 | | | |
| Population - 2010 | 321 | 11,323 | 309,327,143 |
| Population - 2000 | 431 | 12,727 | 285,036,114 |
| Population - 1990 | 229 | 12,849 | 251,960,433 |
| Pop. 2000 to Now | 97.7% | -12.5% | 15.6% |
| Pop. 1990 to Now | 272.1% | -13.4% | 30.8% |
| space4 | | | |
| Population Density | 395.5 | 669.0 | 93.4 |
| Land Area | 1.0 | 15.5 | 3,531,905.4 |
| Water Area | 0.0 | 0.0 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Sandia, TX | Robstown, TX | United States |
| Age 0 to 4 | 0.0% | 6.8% | 5.9% |
| Age 5 to 9 | 7.1% | 10.1% | 6.1% |
| Age 10 to 14 | 6.8% | 4.7% | 6.6% |
| Age 15 to 17 | 0.0% | 3.0% | 3.9% |
| Age 18 to 20 | 0.0% | 2.8% | 4.0% |
| Age 21 to 24 | 0.0% | 7.4% | 5.2% |
| Age 25 to 34 | 0.0% | 12.0% | 13.8% |
| Age 35 to 44 | 21.7% | 11.3% | 12.9% |
| Age 45 to 54 | 0.0% | 8.2% | 12.6% |
| Age 55 to 59 | 24.3% | 5.7% | 6.7% |
| Age 60 to 64 | 3.4% | 5.1% | 6.3% |
| Age 65 to 74 | 6.8% | 10.3% | 9.6% |
| Age 75 to 84 | 29.8% | 4.9% | 4.5% |
| Age 85 and over | 0.0% | 7.6% | 1.9% |
| space1 | | | |
| Race | | | |
| | Sandia, TX | Robstown, TX | United States |
| White | 45.8% | 5.8% | 59.4% |
| Black | 0.0% | 0.1% | 12.2% |
| Asian | 0.0% | 0.0% | 5.6% |
| Native American | 0.0% | 0.0% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.0% | 0.3% | 0.4% |
| Two or More Races | 9.4% | 0.0% | 3.2% |
| Hispanic | 44.8% | 93.8% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Sandia, TX | Robstown, TX | United States |
| Married Population | 82.7% | 38.0% | 49.8% |
| Currently Married | 74.2% | 34.7% | 48.0% |
| Married but Separated | 8.5% | 3.3% | 1.8% |
| Single Population | 17.3% | 62.0% | 50.2% |
| Never Married | 0.0% | 35.0% | 33.8% |
| Divorced | 0.0% | 11.3% | 10.8% |
| Widowed | 17.3% | 15.6% | 5.6% |
| space5 | | | |
| Household Size | 2.08 | 2.69 | 2.60 |
| Households | 184 | 3,822 | 124,010,992 |
| Family Households | 99 | 2,506 | 80,755,759 |
| Married couple, w/children | 36.4% | 20.3% | 30.5% |
| Married couple, no children | 63.6% | 23.9% | 42.9% |
| Non Family Households | 85 | 1,316 | 43,255,233 |
| Single householder, w/children | 0.0% | 27.5% | 15.8% |
| Single householder, no children | 0.0% | 28.3% | 10.8% |