| | Fort Thomas, KY | Madison, AL | United States |
| Population | 17,241 | 55,551 | 329,725,481 |
| Female Population | 49.9% | 50.4% | 50.5% |
| Male Population | 50.1% | 49.6% | 49.5% |
| Median Age | 38.9 | 38.8 | 38.4 |
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| Population - 2010 | 16,181 | 43,558 | 309,327,143 |
| Population - 2000 | 16,495 | 29,329 | 285,036,114 |
| Population - 1990 | 16,032 | 14,904 | 251,960,433 |
| Pop. 2000 to Now | -1.4% | 79.5% | 15.6% |
| Pop. 1990 to Now | 1.4% | 253.3% | 30.8% |
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| Population Density | 3,039.7 | 1,832.4 | 93.4 |
| Land Area | 5.7 | 30.3 | 3,531,905.4 |
| Water Area | 0.8 | 0.1 | 264,836.8 |
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| Est. Total Population By Age | | | |
| | Fort Thomas, KY | Madison, AL | United States |
| Age 0 to 4 | 5.6% | 5.8% | 5.9% |
| Age 5 to 9 | 10.1% | 7.7% | 6.1% |
| Age 10 to 14 | 6.8% | 8.9% | 6.6% |
| Age 15 to 17 | 4.6% | 6.0% | 3.9% |
| Age 18 to 20 | 1.9% | 2.3% | 4.0% |
| Age 21 to 24 | 3.0% | 2.3% | 5.2% |
| Age 25 to 34 | 13.4% | 11.8% | 13.8% |
| Age 35 to 44 | 11.9% | 15.4% | 12.9% |
| Age 45 to 54 | 13.1% | 14.9% | 12.6% |
| Age 55 to 59 | 6.6% | 6.7% | 6.7% |
| Age 60 to 64 | 6.6% | 6.7% | 6.3% |
| Age 65 to 74 | 9.4% | 6.7% | 9.6% |
| Age 75 to 84 | 4.9% | 3.8% | 4.5% |
| Age 85 and over | 2.1% | 1.0% | 1.9% |
| space1 | | | |
| Race | | | |
| | Fort Thomas, KY | Madison, AL | United States |
| White | 92.4% | 69.2% | 59.4% |
| Black | 0.7% | 13.8% | 12.2% |
| Asian | 1.7% | 6.6% | 5.6% |
| Native American | 0.0% | 0.4% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.2% | 0.5% | 0.4% |
| Two or More Races | 3.3% | 2.8% | 3.2% |
| Hispanic | 1.6% | 6.6% | 18.4% |
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| Marriage & Family | | | |
| | Fort Thomas, KY | Madison, AL | United States |
| Married Population | 57.3% | 62.2% | 49.8% |
| Currently Married | 56.8% | 61.4% | 48.0% |
| Married but Separated | 0.5% | 0.9% | 1.8% |
| Single Population | 42.7% | 37.8% | 50.2% |
| Never Married | 24.6% | 24.8% | 33.8% |
| Divorced | 12.4% | 8.0% | 10.8% |
| Widowed | 5.7% | 4.9% | 5.6% |
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| Household Size | 2.59 | 2.59 | 2.60 |
| Households | 6,508 | 21,357 | 124,010,992 |
| Family Households | 4,388 | 15,241 | 80,755,759 |
| Married couple, w/children | 42.2% | 44.7% | 30.5% |
| Married couple, no children | 39.5% | 39.5% | 42.9% |
| Non Family Households | 2,120 | 6,116 | 43,255,233 |
| Single householder, w/children | 12.5% | 12.6% | 15.8% |
| Single householder, no children | 5.8% | 3.2% | 10.8% |