| | Madison, OH | Geneva, OH | United States |
| Population | 3,396 | 5,948 | 329,725,481 |
| Female Population | 52.3% | 52.8% | 50.5% |
| Male Population | 47.7% | 47.2% | 49.5% |
| Median Age | 44.9 | 42.3 | 38.4 |
| space3 | | | |
| Population - 2010 | 3,183 | 6,200 | 309,327,143 |
| Population - 2000 | 2,921 | 6,595 | 285,036,114 |
| Population - 1990 | 2,477 | 6,597 | 251,960,433 |
| Pop. 2000 to Now | 8.2% | -10.6% | 15.6% |
| Pop. 1990 to Now | 27.5% | -10.6% | 30.8% |
| space4 | | | |
| Population Density | 667.6 | 1,458.6 | 93.4 |
| Land Area | 5.1 | 4.1 | 3,531,905.4 |
| Water Area | 0.0 | 0.0 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Madison, OH | Geneva, OH | United States |
| Age 0 to 4 | 3.4% | 4.8% | 5.9% |
| Age 5 to 9 | 6.1% | 4.6% | 6.1% |
| Age 10 to 14 | 6.4% | 5.3% | 6.6% |
| Age 15 to 17 | 6.5% | 5.2% | 3.9% |
| Age 18 to 20 | 2.5% | 1.8% | 4.0% |
| Age 21 to 24 | 4.3% | 9.1% | 5.2% |
| Age 25 to 34 | 10.9% | 13.7% | 13.8% |
| Age 35 to 44 | 10.1% | 8.6% | 12.9% |
| Age 45 to 54 | 15.9% | 14.5% | 12.6% |
| Age 55 to 59 | 7.4% | 5.3% | 6.7% |
| Age 60 to 64 | 7.2% | 8.1% | 6.3% |
| Age 65 to 74 | 10.2% | 9.9% | 9.6% |
| Age 75 to 84 | 5.3% | 6.8% | 4.5% |
| Age 85 and over | 3.7% | 2.3% | 1.9% |
| space1 | | | |
| Race | | | |
| | Madison, OH | Geneva, OH | United States |
| White | 96.8% | 86.3% | 59.4% |
| Black | 1.1% | 3.8% | 12.2% |
| Asian | 0.0% | 0.2% | 5.6% |
| Native American | 0.0% | 0.0% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.4% | 0.0% | 0.4% |
| Two or More Races | 1.7% | 2.5% | 3.2% |
| Hispanic | 0.0% | 7.2% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Madison, OH | Geneva, OH | United States |
| Married Population | 60.3% | 32.5% | 49.8% |
| Currently Married | 60.3% | 30.6% | 48.0% |
| Married but Separated | 0.0% | 1.9% | 1.8% |
| Single Population | 39.7% | 67.5% | 50.2% |
| Never Married | 21.8% | 37.8% | 33.8% |
| Divorced | 11.4% | 19.3% | 10.8% |
| Widowed | 6.5% | 10.4% | 5.6% |
| space5 | | | |
| Household Size | 2.44 | 2.36 | 2.60 |
| Households | 1,388 | 2,372 | 124,010,992 |
| Family Households | 911 | 1,125 | 80,755,759 |
| Married couple, w/children | 37.5% | 30.4% | 30.5% |
| Married couple, no children | 56.0% | 36.3% | 42.9% |
| Non Family Households | 477 | 1,247 | 43,255,233 |
| Single householder, w/children | 4.7% | 23.8% | 15.8% |
| Single householder, no children | 1.8% | 9.5% | 10.8% |