| | Duxbury, MA | Northampton, MA | United States |
| Population | 16,004 | 29,379 | 329,725,481 |
| Female Population | 51.8% | 58.4% | 50.5% |
| Male Population | 48.2% | 41.6% | 49.5% |
| Median Age | 47.6 | 41 | 38.4 |
| space3 | | | |
| Population - 2010 | 15,082 | 28,663 | 309,327,143 |
| Population - 2000 | 14,248 | 28,978 | 285,036,114 |
| Population - 1990 | 13,895 | 29,289 | 251,960,433 |
| Pop. 2000 to Now | 11.8% | -2.1% | 15.6% |
| Pop. 1990 to Now | 14.7% | -3.2% | 30.8% |
| space4 | | | |
| Population Density | 674.2 | 857.9 | 93.4 |
| Land Area | 23.7 | 34.2 | 3,531,905.4 |
| Water Area | 13.9 | 1.5 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Duxbury, MA | Northampton, MA | United States |
| Age 0 to 4 | 4.6% | 2.5% | 5.9% |
| Age 5 to 9 | 6.1% | 4.4% | 6.1% |
| Age 10 to 14 | 8.0% | 5.2% | 6.6% |
| Age 15 to 17 | 4.4% | 3.2% | 3.9% |
| Age 18 to 20 | 2.0% | 7.7% | 4.0% |
| Age 21 to 24 | 3.6% | 8.1% | 5.2% |
| Age 25 to 34 | 6.4% | 12.2% | 13.8% |
| Age 35 to 44 | 9.9% | 11.9% | 12.9% |
| Age 45 to 54 | 16.0% | 12.3% | 12.6% |
| Age 55 to 59 | 7.7% | 6.3% | 6.7% |
| Age 60 to 64 | 7.1% | 6.8% | 6.3% |
| Age 65 to 74 | 14.1% | 12.7% | 9.6% |
| Age 75 to 84 | 6.5% | 4.5% | 4.5% |
| Age 85 and over | 3.5% | 2.2% | 1.9% |
| space1 | | | |
| Race | | | |
| | Duxbury, MA | Northampton, MA | United States |
| White | 96.0% | 82.4% | 59.4% |
| Black | 0.4% | 2.6% | 12.2% |
| Asian | 1.3% | 3.5% | 5.6% |
| Native American | 0.1% | 0.1% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.0% | 0.3% | 0.4% |
| Two or More Races | 1.3% | 3.7% | 3.2% |
| Hispanic | 1.0% | 7.4% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Duxbury, MA | Northampton, MA | United States |
| Married Population | 63.0% | 41.1% | 49.8% |
| Currently Married | 61.7% | 40.1% | 48.0% |
| Married but Separated | 1.2% | 1.0% | 1.8% |
| Single Population | 37.0% | 58.9% | 50.2% |
| Never Married | 22.3% | 42.2% | 33.8% |
| Divorced | 6.3% | 11.5% | 10.8% |
| Widowed | 8.4% | 5.2% | 5.6% |
| space5 | | | |
| Household Size | 2.60 | 2.13 | 2.60 |
| Households | 6,092 | 11,949 | 124,010,992 |
| Family Households | 4,515 | 6,478 | 80,755,759 |
| Married couple, w/children | 38.9% | 30.2% | 30.5% |
| Married couple, no children | 48.6% | 45.8% | 42.9% |
| Non Family Households | 1,577 | 5,471 | 43,255,233 |
| Single householder, w/children | 6.2% | 13.1% | 15.8% |
| Single householder, no children | 6.3% | 10.9% | 10.8% |