| | Southbury, CT | Stratford, CT | United States |
| Population | 19,866 | 52,360 | 329,725,481 |
| Female Population | 52.8% | 52.5% | 50.5% |
| Male Population | 47.2% | 47.6% | 49.5% |
| Median Age | 50.8 | 43.4 | 38.4 |
| space3 | | | |
| Population - 2010 | 19,900 | 51,441 | 309,327,143 |
| Population - 2000 | 18,567 | 49,976 | 285,036,114 |
| Population - 1990 | 15,818 | 49,389 | 251,960,433 |
| Pop. 2000 to Now | 5.0% | 3.4% | 15.6% |
| Pop. 1990 to Now | 23.3% | 4.6% | 30.8% |
| space4 | | | |
| Population Density | 509.5 | 2,994.2 | 93.4 |
| Land Area | 39.0 | 17.5 | 3,531,905.4 |
| Water Area | 1.1 | 2.4 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Southbury, CT | Stratford, CT | United States |
| Age 0 to 4 | 4.0% | 4.5% | 5.9% |
| Age 5 to 9 | 4.2% | 4.4% | 6.1% |
| Age 10 to 14 | 7.0% | 6.5% | 6.6% |
| Age 15 to 17 | 4.1% | 3.8% | 3.9% |
| Age 18 to 20 | 2.6% | 3.1% | 4.0% |
| Age 21 to 24 | 3.5% | 5.8% | 5.2% |
| Age 25 to 34 | 7.5% | 11.6% | 13.8% |
| Age 35 to 44 | 10.3% | 12.0% | 12.9% |
| Age 45 to 54 | 13.8% | 14.1% | 12.6% |
| Age 55 to 59 | 7.3% | 7.0% | 6.7% |
| Age 60 to 64 | 7.1% | 7.5% | 6.3% |
| Age 65 to 74 | 13.7% | 10.7% | 9.6% |
| Age 75 to 84 | 9.3% | 5.8% | 4.5% |
| Age 85 and over | 5.5% | 3.1% | 1.9% |
| space1 | | | |
| Race | | | |
| | Southbury, CT | Stratford, CT | United States |
| White | 86.3% | 56.3% | 59.4% |
| Black | 2.1% | 19.7% | 12.2% |
| Asian | 3.2% | 1.4% | 5.6% |
| Native American | 0.0% | 0.0% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.1% | 0.2% |
| Other | 0.2% | 0.2% | 0.4% |
| Two or More Races | 1.7% | 2.2% | 3.2% |
| Hispanic | 6.4% | 20.1% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Southbury, CT | Stratford, CT | United States |
| Married Population | 57.0% | 48.2% | 49.8% |
| Currently Married | 56.6% | 47.2% | 48.0% |
| Married but Separated | 0.4% | 0.9% | 1.8% |
| Single Population | 43.0% | 51.8% | 50.2% |
| Never Married | 22.9% | 34.2% | 33.8% |
| Divorced | 11.9% | 10.7% | 10.8% |
| Widowed | 8.2% | 7.0% | 5.6% |
| space5 | | | |
| Household Size | 2.42 | 2.58 | 2.60 |
| Households | 8,029 | 20,187 | 124,010,992 |
| Family Households | 5,199 | 13,849 | 80,755,759 |
| Married couple, w/children | 33.0% | 26.1% | 30.5% |
| Married couple, no children | 54.3% | 44.7% | 42.9% |
| Non Family Households | 2,830 | 6,338 | 43,255,233 |
| Single householder, w/children | 4.4% | 14.4% | 15.8% |
| Single householder, no children | 8.2% | 14.8% | 10.8% |