| | Macon, IL | Illiopolis, IL | United States |
| Population | 1,056 | 886 | 329,725,481 |
| Female Population | 53.9% | 47.2% | 50.5% |
| Male Population | 46.1% | 52.8% | 49.5% |
| Median Age | 41.7 | 36.8 | 38.4 |
| space3 | | | |
| Population - 2010 | 1,153 | 892 | 309,327,143 |
| Population - 2000 | 1,213 | 916 | 285,036,114 |
| Population - 1990 | 1,282 | 934 | 251,960,433 |
| Pop. 2000 to Now | -9.2% | -8.8% | 15.6% |
| Pop. 1990 to Now | -14.0% | -10.6% | 30.8% |
| space4 | | | |
| Population Density | 727.8 | 1,934.5 | 93.4 |
| Land Area | 1.5 | 0.5 | 3,531,905.4 |
| Water Area | 0.0 | 0.0 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Macon, IL | Illiopolis, IL | United States |
| Age 0 to 4 | 7.2% | 8.6% | 5.9% |
| Age 5 to 9 | 7.1% | 7.7% | 6.1% |
| Age 10 to 14 | 6.4% | 9.7% | 6.6% |
| Age 15 to 17 | 2.3% | 3.2% | 3.9% |
| Age 18 to 20 | 2.0% | 1.2% | 4.0% |
| Age 21 to 24 | 3.1% | 3.8% | 5.2% |
| Age 25 to 34 | 14.8% | 11.3% | 13.8% |
| Age 35 to 44 | 10.0% | 13.4% | 12.9% |
| Age 45 to 54 | 11.8% | 10.6% | 12.6% |
| Age 55 to 59 | 5.7% | 8.5% | 6.7% |
| Age 60 to 64 | 9.4% | 7.8% | 6.3% |
| Age 65 to 74 | 12.1% | 8.1% | 9.6% |
| Age 75 to 84 | 4.5% | 4.5% | 4.5% |
| Age 85 and over | 3.6% | 1.6% | 1.9% |
| space1 | | | |
| Race | | | |
| | Macon, IL | Illiopolis, IL | United States |
| White | 94.2% | 97.1% | 59.4% |
| Black | 1.6% | 0.5% | 12.2% |
| Asian | 0.0% | 0.1% | 5.6% |
| Native American | 0.0% | 0.0% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 1.6% | 0.0% | 0.4% |
| Two or More Races | 1.7% | 1.6% | 3.2% |
| Hispanic | 0.9% | 0.8% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Macon, IL | Illiopolis, IL | United States |
| Married Population | 59.4% | 55.6% | 49.8% |
| Currently Married | 59.4% | 55.2% | 48.0% |
| Married but Separated | 0.0% | 0.5% | 1.8% |
| Single Population | 40.6% | 44.4% | 50.2% |
| Never Married | 22.3% | 22.9% | 33.8% |
| Divorced | 10.9% | 12.0% | 10.8% |
| Widowed | 7.4% | 9.5% | 5.6% |
| space5 | | | |
| Household Size | 2.38 | 2.47 | 2.60 |
| Households | 444 | 358 | 124,010,992 |
| Family Households | 310 | 229 | 80,755,759 |
| Married couple, w/children | 30.0% | 33.2% | 30.5% |
| Married couple, no children | 48.7% | 39.7% | 42.9% |
| Non Family Households | 134 | 129 | 43,255,233 |
| Single householder, w/children | 11.0% | 19.7% | 15.8% |
| Single householder, no children | 10.3% | 7.4% | 10.8% |