| | Northfield, VT | St. James City, FL | United States |
| Population | 6,271 | 3,551 | 329,725,481 |
| Female Population | 42.6% | 46.3% | 50.5% |
| Male Population | 57.4% | 53.7% | 49.5% |
| Median Age | 27.3 | 63.7 | 38.4 |
| space3 | | | |
| Population - 2010 | 6,214 | 3,347 | 309,327,143 |
| Population - 2000 | 5,791 | 4,105 | 285,036,114 |
| Population - 1990 | 5,610 | 1,904 | 251,960,433 |
| Pop. 2000 to Now | 12.3% | 1.0% | 15.6% |
| Pop. 1990 to Now | 15.9% | 117.8% | 30.8% |
| space4 | | | |
| Population Density | 144.2 | 243.1 | 93.4 |
| Land Area | 43.5 | 14.6 | 3,531,905.4 |
| Water Area | 0.1 | 2.1 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Northfield, VT | St. James City, FL | United States |
| Age 0 to 4 | 4.8% | 0.0% | 5.9% |
| Age 5 to 9 | 4.5% | 3.9% | 6.1% |
| Age 10 to 14 | 1.9% | 1.2% | 6.6% |
| Age 15 to 17 | 1.1% | 1.4% | 3.9% |
| Age 18 to 20 | 18.3% | 1.0% | 4.0% |
| Age 21 to 24 | 16.2% | 1.2% | 5.2% |
| Age 25 to 34 | 13.4% | 5.5% | 13.8% |
| Age 35 to 44 | 2.7% | 1.0% | 12.9% |
| Age 45 to 54 | 10.0% | 18.6% | 12.6% |
| Age 55 to 59 | 6.3% | 9.2% | 6.7% |
| Age 60 to 64 | 4.4% | 12.2% | 6.3% |
| Age 65 to 74 | 9.4% | 29.0% | 9.6% |
| Age 75 to 84 | 3.9% | 12.1% | 4.5% |
| Age 85 and over | 3.3% | 3.9% | 1.9% |
| space1 | | | |
| Race | | | |
| | Northfield, VT | St. James City, FL | United States |
| White | 87.7% | 96.1% | 59.4% |
| Black | 0.5% | 0.0% | 12.2% |
| Asian | 1.6% | 0.4% | 5.6% |
| Native American | 0.7% | 0.0% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 1.0% | 0.2% |
| Other | 0.0% | 0.0% | 0.4% |
| Two or More Races | 4.2% | 1.0% | 3.2% |
| Hispanic | 5.3% | 1.5% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Northfield, VT | St. James City, FL | United States |
| Married Population | 36.2% | 61.8% | 49.8% |
| Currently Married | 35.6% | 61.4% | 48.0% |
| Married but Separated | 0.6% | 0.4% | 1.8% |
| Single Population | 63.8% | 38.2% | 50.2% |
| Never Married | 49.8% | 13.9% | 33.8% |
| Divorced | 7.8% | 15.2% | 10.8% |
| Widowed | 6.2% | 9.1% | 5.6% |
| space5 | | | |
| Household Size | 2.37 | 2.07 | 2.60 |
| Households | 1,873 | 1,719 | 124,010,992 |
| Family Households | 1,078 | 1,129 | 80,755,759 |
| Married couple, w/children | 24.8% | 11.3% | 30.5% |
| Married couple, no children | 56.9% | 76.0% | 42.9% |
| Non Family Households | 795 | 590 | 43,255,233 |
| Single householder, w/children | 12.2% | 5.1% | 15.8% |
| Single householder, no children | 6.2% | 7.5% | 10.8% |