| | Madison, CT | Vienna, VA | United States |
| Population | 17,742 | 16,465 | 329,725,481 |
| Female Population | 51.0% | 52.0% | 50.5% |
| Male Population | 49.0% | 48.0% | 49.5% |
| Median Age | 50.8 | 41.7 | 38.4 |
| space3 | | | |
| Population - 2010 | 18,267 | 15,743 | 309,327,143 |
| Population - 2000 | 17,858 | 14,453 | 285,036,114 |
| Population - 1990 | 15,485 | 14,852 | 251,960,433 |
| Pop. 2000 to Now | 0.4% | 14.3% | 15.6% |
| Pop. 1990 to Now | 15.8% | 11.2% | 30.8% |
| space4 | | | |
| Population Density | 490.8 | 3,739.5 | 93.4 |
| Land Area | 36.1 | 4.4 | 3,531,905.4 |
| Water Area | 0.5 | 0.0 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Madison, CT | Vienna, VA | United States |
| Age 0 to 4 | 3.1% | 5.8% | 5.9% |
| Age 5 to 9 | 4.1% | 7.7% | 6.1% |
| Age 10 to 14 | 7.6% | 9.7% | 6.6% |
| Age 15 to 17 | 4.2% | 4.7% | 3.9% |
| Age 18 to 20 | 3.7% | 2.8% | 4.0% |
| Age 21 to 24 | 3.7% | 2.7% | 5.2% |
| Age 25 to 34 | 6.1% | 7.0% | 13.8% |
| Age 35 to 44 | 8.9% | 14.3% | 12.9% |
| Age 45 to 54 | 15.8% | 15.9% | 12.6% |
| Age 55 to 59 | 10.8% | 8.0% | 6.7% |
| Age 60 to 64 | 8.6% | 7.5% | 6.3% |
| Age 65 to 74 | 14.5% | 8.0% | 9.6% |
| Age 75 to 84 | 5.7% | 3.4% | 4.5% |
| Age 85 and over | 3.1% | 2.5% | 1.9% |
| space1 | | | |
| Race | | | |
| | Madison, CT | Vienna, VA | United States |
| White | 90.0% | 67.5% | 59.4% |
| Black | 0.5% | 2.2% | 12.2% |
| Asian | 3.0% | 13.7% | 5.6% |
| Native American | 0.2% | 0.4% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.1% | 0.3% | 0.4% |
| Two or More Races | 3.5% | 6.1% | 3.2% |
| Hispanic | 2.8% | 9.8% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Madison, CT | Vienna, VA | United States |
| Married Population | 64.9% | 65.7% | 49.8% |
| Currently Married | 64.1% | 64.8% | 48.0% |
| Married but Separated | 0.8% | 1.0% | 1.8% |
| Single Population | 35.1% | 34.3% | 50.2% |
| Never Married | 23.1% | 22.3% | 33.8% |
| Divorced | 7.8% | 7.9% | 10.8% |
| Widowed | 4.2% | 4.1% | 5.6% |
| space5 | | | |
| Household Size | 2.61 | 3.03 | 2.60 |
| Households | 6,719 | 5,424 | 124,010,992 |
| Family Households | 5,221 | 4,430 | 80,755,759 |
| Married couple, w/children | 29.9% | 44.4% | 30.5% |
| Married couple, no children | 60.4% | 40.8% | 42.9% |
| Non Family Households | 1,498 | 994 | 43,255,233 |
| Single householder, w/children | 5.4% | 8.6% | 15.8% |
| Single householder, no children | 4.2% | 6.2% | 10.8% |