| | Vandalia, IL | Carbondale, IL | United States |
| Population | 6,459 | 22,388 | 329,725,481 |
| Female Population | 39.8% | 48.9% | 50.5% |
| Male Population | 60.2% | 51.1% | 49.5% |
| Median Age | 41.7 | 24.8 | 38.4 |
| space3 | | | |
| Population - 2010 | 7,038 | 26,517 | 309,327,143 |
| Population - 2000 | 6,975 | 20,681 | 285,036,114 |
| Population - 1990 | 6,114 | 27,033 | 251,960,433 |
| Pop. 2000 to Now | -4.5% | 21.1% | 15.6% |
| Pop. 1990 to Now | 9.0% | -7.4% | 30.8% |
| space4 | | | |
| Population Density | 792.8 | 1,295.9 | 93.4 |
| Land Area | 8.1 | 17.3 | 3,531,905.4 |
| Water Area | 0.0 | 0.4 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Vandalia, IL | Carbondale, IL | United States |
| Age 0 to 4 | 4.8% | 2.2% | 5.9% |
| Age 5 to 9 | 4.5% | 3.4% | 6.1% |
| Age 10 to 14 | 4.0% | 3.3% | 6.6% |
| Age 15 to 17 | 2.9% | 3.0% | 3.9% |
| Age 18 to 20 | 3.9% | 16.7% | 4.0% |
| Age 21 to 24 | 6.0% | 22.8% | 5.2% |
| Age 25 to 34 | 15.4% | 15.5% | 13.8% |
| Age 35 to 44 | 13.4% | 8.3% | 12.9% |
| Age 45 to 54 | 13.1% | 7.0% | 12.6% |
| Age 55 to 59 | 8.6% | 4.2% | 6.7% |
| Age 60 to 64 | 7.4% | 3.6% | 6.3% |
| Age 65 to 74 | 8.4% | 6.2% | 9.6% |
| Age 75 to 84 | 6.0% | 2.0% | 4.5% |
| Age 85 and over | 1.6% | 1.9% | 1.9% |
| space1 | | | |
| Race | | | |
| | Vandalia, IL | Carbondale, IL | United States |
| White | 79.7% | 56.6% | 59.4% |
| Black | 13.9% | 27.4% | 12.2% |
| Asian | 0.0% | 7.0% | 5.6% |
| Native American | 0.3% | 0.2% | 0.6% |
| Hawaiian, Pacific Islander | 0.2% | 0.1% | 0.2% |
| Other | 0.0% | 0.5% | 0.4% |
| Two or More Races | 0.4% | 3.2% | 3.2% |
| Hispanic | 5.5% | 5.0% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Vandalia, IL | Carbondale, IL | United States |
| Married Population | 35.3% | 21.6% | 49.8% |
| Currently Married | 34.0% | 19.5% | 48.0% |
| Married but Separated | 1.3% | 2.1% | 1.8% |
| Single Population | 64.7% | 78.4% | 50.2% |
| Never Married | 44.5% | 68.0% | 33.8% |
| Divorced | 13.3% | 6.9% | 10.8% |
| Widowed | 6.9% | 3.4% | 5.6% |
| space5 | | | |
| Household Size | 2.43 | 1.86 | 2.60 |
| Households | 2,090 | 10,193 | 124,010,992 |
| Family Households | 1,166 | 3,139 | 80,755,759 |
| Married couple, w/children | 23.8% | 19.4% | 30.5% |
| Married couple, no children | 45.0% | 34.8% | 42.9% |
| Non Family Households | 924 | 7,054 | 43,255,233 |
| Single householder, w/children | 20.6% | 27.4% | 15.8% |
| Single householder, no children | 10.6% | 18.4% | 10.8% |