| | Smyrna, TN | Roswell, GA | United States |
| Population | 52,401 | 92,688 | 329,725,481 |
| Female Population | 50.6% | 50.4% | 50.5% |
| Male Population | 49.4% | 49.6% | 49.5% |
| Median Age | 34.4 | 40.2 | 38.4 |
| space3 | | | |
| Population - 2010 | 40,589 | 88,799 | 309,327,143 |
| Population - 2000 | 25,569 | 79,334 | 285,036,114 |
| Population - 1990 | 13,647 | 47,923 | 251,960,433 |
| Pop. 2000 to Now | 108.0% | 20.3% | 15.6% |
| Pop. 1990 to Now | 289.7% | 99.1% | 30.8% |
| space4 | | | |
| Population Density | 1,729.0 | 2,276.4 | 93.4 |
| Land Area | 30.3 | 40.7 | 3,531,905.4 |
| Water Area | 0.1 | 1.3 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Smyrna, TN | Roswell, GA | United States |
| Age 0 to 4 | 7.6% | 5.3% | 5.9% |
| Age 5 to 9 | 7.3% | 6.5% | 6.1% |
| Age 10 to 14 | 6.8% | 7.9% | 6.6% |
| Age 15 to 17 | 3.5% | 5.2% | 3.9% |
| Age 18 to 20 | 4.2% | 3.5% | 4.0% |
| Age 21 to 24 | 5.3% | 3.6% | 5.2% |
| Age 25 to 34 | 16.3% | 10.8% | 13.8% |
| Age 35 to 44 | 14.9% | 14.5% | 12.9% |
| Age 45 to 54 | 13.0% | 15.4% | 12.6% |
| Age 55 to 59 | 6.4% | 6.4% | 6.7% |
| Age 60 to 64 | 5.1% | 6.5% | 6.3% |
| Age 65 to 74 | 5.9% | 9.5% | 9.6% |
| Age 75 to 84 | 3.0% | 3.7% | 4.5% |
| Age 85 and over | 0.7% | 1.2% | 1.9% |
| space1 | | | |
| Race | | | |
| | Smyrna, TN | Roswell, GA | United States |
| White | 61.6% | 61.9% | 59.4% |
| Black | 17.0% | 11.9% | 12.2% |
| Asian | 5.0% | 4.1% | 5.6% |
| Native American | 0.2% | 0.1% | 0.6% |
| Hawaiian, Pacific Islander | 0.1% | 0.0% | 0.2% |
| Other | 0.3% | 1.2% | 0.4% |
| Two or More Races | 3.6% | 3.8% | 3.2% |
| Hispanic | 12.3% | 17.1% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Smyrna, TN | Roswell, GA | United States |
| Married Population | 48.3% | 57.4% | 49.8% |
| Currently Married | 47.2% | 56.1% | 48.0% |
| Married but Separated | 1.1% | 1.3% | 1.8% |
| Single Population | 51.7% | 42.6% | 50.2% |
| Never Married | 34.2% | 29.2% | 33.8% |
| Divorced | 11.6% | 9.7% | 10.8% |
| Widowed | 5.9% | 3.7% | 5.6% |
| space5 | | | |
| Household Size | 2.74 | 2.61 | 2.60 |
| Households | 19,022 | 35,337 | 124,010,992 |
| Family Households | 13,173 | 24,175 | 80,755,759 |
| Married couple, w/children | 31.5% | 36.8% | 30.5% |
| Married couple, no children | 36.2% | 44.3% | 42.9% |
| Non Family Households | 5,849 | 11,162 | 43,255,233 |
| Single householder, w/children | 20.4% | 11.1% | 15.8% |
| Single householder, no children | 12.0% | 7.8% | 10.8% |