| | Paducah, KY | Rancho Cordova, CA | United States |
| Population | 26,248 | 78,358 | 329,725,481 |
| Female Population | 53.5% | 50.7% | 50.5% |
| Male Population | 46.5% | 49.3% | 49.5% |
| Median Age | 43.7 | 34.7 | 38.4 |
| space3 | | | |
| Population - 2010 | 24,983 | 65,019 | 309,327,143 |
| Population - 2000 | 26,307 | 55,060 | 285,036,114 |
| Population - 1990 | 27,256 | 48,731 | 251,960,433 |
| Pop. 2000 to Now | -5.4% | 38.3% | 15.6% |
| Pop. 1990 to Now | -8.7% | 56.3% | 30.8% |
| space4 | | | |
| Population Density | 1,299.5 | 2,237.5 | 93.4 |
| Land Area | 20.2 | 35.0 | 3,531,905.4 |
| Water Area | 0.4 | 0.3 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Paducah, KY | Rancho Cordova, CA | United States |
| Age 0 to 4 | 4.7% | 7.9% | 5.9% |
| Age 5 to 9 | 5.4% | 7.5% | 6.1% |
| Age 10 to 14 | 5.1% | 7.0% | 6.6% |
| Age 15 to 17 | 4.1% | 3.5% | 3.9% |
| Age 18 to 20 | 4.7% | 2.7% | 4.0% |
| Age 21 to 24 | 3.5% | 5.0% | 5.2% |
| Age 25 to 34 | 12.2% | 16.8% | 13.8% |
| Age 35 to 44 | 12.8% | 14.7% | 12.9% |
| Age 45 to 54 | 13.3% | 11.4% | 12.6% |
| Age 55 to 59 | 7.3% | 6.2% | 6.7% |
| Age 60 to 64 | 7.9% | 5.7% | 6.3% |
| Age 65 to 74 | 10.8% | 7.0% | 9.6% |
| Age 75 to 84 | 5.4% | 3.4% | 4.5% |
| Age 85 and over | 2.8% | 1.2% | 1.9% |
| space1 | | | |
| Race | | | |
| | Paducah, KY | Rancho Cordova, CA | United States |
| White | 70.2% | 47.7% | 59.4% |
| Black | 22.3% | 10.6% | 12.2% |
| Asian | 1.4% | 13.8% | 5.6% |
| Native American | 0.5% | 0.2% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.7% | 0.2% |
| Other | 0.3% | 0.4% | 0.4% |
| Two or More Races | 2.5% | 5.7% | 3.2% |
| Hispanic | 2.7% | 20.9% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Paducah, KY | Rancho Cordova, CA | United States |
| Married Population | 43.0% | 50.3% | 49.8% |
| Currently Married | 39.8% | 47.6% | 48.0% |
| Married but Separated | 3.2% | 2.7% | 1.8% |
| Single Population | 57.0% | 49.7% | 50.2% |
| Never Married | 31.8% | 33.9% | 33.8% |
| Divorced | 16.1% | 11.3% | 10.8% |
| Widowed | 9.1% | 4.5% | 5.6% |
| space5 | | | |
| Household Size | 2.19 | 2.91 | 2.60 |
| Households | 11,493 | 26,725 | 124,010,992 |
| Family Households | 6,004 | 18,431 | 80,755,759 |
| Married couple, w/children | 21.4% | 37.2% | 30.5% |
| Married couple, no children | 42.4% | 33.4% | 42.9% |
| Non Family Households | 5,489 | 8,294 | 43,255,233 |
| Single householder, w/children | 24.2% | 15.7% | 15.8% |
| Single householder, no children | 12.0% | 13.7% | 10.8% |