| | Toms Brook, VA | South Riding, VA | United States |
| Population | 449 | 33,828 | 329,725,481 |
| Female Population | 48.8% | 49.0% | 50.5% |
| Male Population | 51.2% | 51.0% | 49.5% |
| Median Age | 35.3 | 36.9 | 38.4 |
| space3 | | | |
| Population - 2010 | 265 | 22,982 | 309,327,143 |
| Population - 2000 | 255 | 6,307 | 285,036,114 |
| Population - 1990 | 227 | 1,369 | 251,960,433 |
| Pop. 2000 to Now | 7.1% | 445.1% | 15.6% |
| Pop. 1990 to Now | 20.3% | 2,411.3% | 30.8% |
| space4 | | | |
| Population Density | 3,563.5 | 4,934.8 | 93.4 |
| Land Area | 0.1 | 6.9 | 3,531,905.4 |
| Water Area | 0.0 | 0.1 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Toms Brook, VA | South Riding, VA | United States |
| Age 0 to 4 | 9.4% | 6.0% | 5.9% |
| Age 5 to 9 | 10.0% | 9.1% | 6.1% |
| Age 10 to 14 | 8.0% | 9.9% | 6.6% |
| Age 15 to 17 | 4.5% | 5.2% | 3.9% |
| Age 18 to 20 | 0.9% | 3.9% | 4.0% |
| Age 21 to 24 | 2.2% | 2.4% | 5.2% |
| Age 25 to 34 | 14.3% | 10.8% | 13.8% |
| Age 35 to 44 | 12.2% | 20.2% | 12.9% |
| Age 45 to 54 | 17.1% | 17.5% | 12.6% |
| Age 55 to 59 | 6.0% | 6.1% | 6.7% |
| Age 60 to 64 | 3.3% | 3.6% | 6.3% |
| Age 65 to 74 | 6.7% | 3.7% | 9.6% |
| Age 75 to 84 | 3.8% | 1.4% | 4.5% |
| Age 85 and over | 1.6% | 0.2% | 1.9% |
| space1 | | | |
| Race | | | |
| | Toms Brook, VA | South Riding, VA | United States |
| White | 94.9% | 41.4% | 59.4% |
| Black | 3.6% | 8.1% | 12.2% |
| Asian | 0.0% | 35.3% | 5.6% |
| Native American | 0.0% | 0.2% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.0% | 1.5% | 0.4% |
| Two or More Races | 1.1% | 4.4% | 3.2% |
| Hispanic | 0.4% | 9.0% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Toms Brook, VA | South Riding, VA | United States |
| Married Population | 35.3% | 68.7% | 49.8% |
| Currently Married | 33.7% | 67.5% | 48.0% |
| Married but Separated | 1.5% | 1.2% | 1.8% |
| Single Population | 64.7% | 31.3% | 50.2% |
| Never Married | 45.1% | 23.5% | 33.8% |
| Divorced | 10.4% | 5.6% | 10.8% |
| Widowed | 9.2% | 2.2% | 5.6% |
| space5 | | | |
| Household Size | 3.30 | 3.27 | 2.60 |
| Households | 136 | 10,353 | 124,010,992 |
| Family Households | 98 | 9,075 | 80,755,759 |
| Married couple, w/children | 29.6% | 56.6% | 30.5% |
| Married couple, no children | 15.3% | 30.1% | 42.9% |
| Non Family Households | 38 | 1,278 | 43,255,233 |
| Single householder, w/children | 30.6% | 9.5% | 15.8% |
| Single householder, no children | 24.5% | 3.7% | 10.8% |