| | Rantoul, IL | DeKalb, IL | United States |
| Population | 12,766 | 41,083 | 329,725,481 |
| Female Population | 53.2% | 50.4% | 50.5% |
| Male Population | 46.8% | 49.6% | 49.5% |
| Median Age | 35 | 25.1 | 38.4 |
| space3 | | | |
| Population - 2010 | 12,972 | 44,107 | 309,327,143 |
| Population - 2000 | 12,857 | 39,018 | 285,036,114 |
| Population - 1990 | 17,212 | 34,925 | 251,960,433 |
| Pop. 2000 to Now | -4.3% | 9.2% | 15.6% |
| Pop. 1990 to Now | -28.5% | 22.0% | 30.8% |
| space4 | | | |
| Population Density | 1,503.7 | 2,545.6 | 93.4 |
| Land Area | 8.5 | 16.1 | 3,531,905.4 |
| Water Area | 0.1 | 0.2 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Rantoul, IL | DeKalb, IL | United States |
| Age 0 to 4 | 8.8% | 5.1% | 5.9% |
| Age 5 to 9 | 5.8% | 5.2% | 6.1% |
| Age 10 to 14 | 6.3% | 5.6% | 6.6% |
| Age 15 to 17 | 7.4% | 3.1% | 3.9% |
| Age 18 to 20 | 2.7% | 13.0% | 4.0% |
| Age 21 to 24 | 6.0% | 17.9% | 5.2% |
| Age 25 to 34 | 12.9% | 14.5% | 13.8% |
| Age 35 to 44 | 12.9% | 9.4% | 12.9% |
| Age 45 to 54 | 10.7% | 8.2% | 12.6% |
| Age 55 to 59 | 6.8% | 4.9% | 6.7% |
| Age 60 to 64 | 7.1% | 3.5% | 6.3% |
| Age 65 to 74 | 7.3% | 5.5% | 9.6% |
| Age 75 to 84 | 3.2% | 2.4% | 4.5% |
| Age 85 and over | 2.0% | 1.8% | 1.9% |
| space1 | | | |
| Race | | | |
| | Rantoul, IL | DeKalb, IL | United States |
| White | 52.7% | 60.5% | 59.4% |
| Black | 18.8% | 14.5% | 12.2% |
| Asian | 1.6% | 4.0% | 5.6% |
| Native American | 0.3% | 0.1% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.0% | 0.2% | 0.4% |
| Two or More Races | 13.9% | 4.6% | 3.2% |
| Hispanic | 12.7% | 16.1% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Rantoul, IL | DeKalb, IL | United States |
| Married Population | 37.4% | 30.8% | 49.8% |
| Currently Married | 35.1% | 30.1% | 48.0% |
| Married but Separated | 2.3% | 0.8% | 1.8% |
| Single Population | 62.6% | 69.2% | 50.2% |
| Never Married | 42.3% | 58.0% | 33.8% |
| Divorced | 14.1% | 7.2% | 10.8% |
| Widowed | 6.2% | 4.0% | 5.6% |
| space5 | | | |
| Household Size | 2.44 | 2.35 | 2.60 |
| Households | 5,123 | 15,867 | 124,010,992 |
| Family Households | 2,936 | 7,826 | 80,755,759 |
| Married couple, w/children | 16.9% | 26.7% | 30.5% |
| Married couple, no children | 37.6% | 35.8% | 42.9% |
| Non Family Households | 2,187 | 8,041 | 43,255,233 |
| Single householder, w/children | 35.0% | 25.3% | 15.8% |
| Single householder, no children | 10.5% | 12.3% | 10.8% |