| | Plympton, MA | Norwell, MA | United States |
| Population | 2,934 | 11,258 | 329,725,481 |
| Female Population | 52.1% | 49.8% | 50.5% |
| Male Population | 47.9% | 50.2% | 49.5% |
| Median Age | 45.5 | 39 | 38.4 |
| space3 | | | |
| Population - 2010 | 2,847 | 10,529 | 309,327,143 |
| Population - 2000 | 2,637 | 9,765 | 285,036,114 |
| Population - 1990 | 2,384 | 9,279 | 251,960,433 |
| Pop. 2000 to Now | 13.7% | 14.4% | 15.6% |
| Pop. 1990 to Now | 25.8% | 20.4% | 30.8% |
| space4 | | | |
| Population Density | 200.0 | 537.9 | 93.4 |
| Land Area | 14.7 | 20.9 | 3,531,905.4 |
| Water Area | 0.4 | 0.3 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Plympton, MA | Norwell, MA | United States |
| Age 0 to 4 | 5.5% | 8.2% | 5.9% |
| Age 5 to 9 | 5.9% | 7.8% | 6.1% |
| Age 10 to 14 | 8.9% | 7.2% | 6.6% |
| Age 15 to 17 | 2.6% | 6.2% | 3.9% |
| Age 18 to 20 | 4.3% | 3.0% | 4.0% |
| Age 21 to 24 | 1.8% | 3.2% | 5.2% |
| Age 25 to 34 | 10.3% | 9.3% | 13.8% |
| Age 35 to 44 | 9.9% | 12.9% | 12.9% |
| Age 45 to 54 | 17.6% | 16.5% | 12.6% |
| Age 55 to 59 | 5.8% | 7.3% | 6.7% |
| Age 60 to 64 | 6.1% | 3.5% | 6.3% |
| Age 65 to 74 | 14.0% | 8.0% | 9.6% |
| Age 75 to 84 | 5.4% | 4.9% | 4.5% |
| Age 85 and over | 2.0% | 2.1% | 1.9% |
| space1 | | | |
| Race | | | |
| | Plympton, MA | Norwell, MA | United States |
| White | 96.1% | 91.7% | 59.4% |
| Black | 2.7% | 0.2% | 12.2% |
| Asian | 0.0% | 4.1% | 5.6% |
| Native American | 0.0% | 0.0% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.2% | 0.2% |
| Other | 0.0% | 0.1% | 0.4% |
| Two or More Races | 0.7% | 1.0% | 3.2% |
| Hispanic | 0.5% | 2.8% | 18.4% |
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| Marriage & Family | | | |
| | Plympton, MA | Norwell, MA | United States |
| Married Population | 65.6% | 63.7% | 49.8% |
| Currently Married | 64.3% | 63.3% | 48.0% |
| Married but Separated | 1.3% | 0.4% | 1.8% |
| Single Population | 34.4% | 36.3% | 50.2% |
| Never Married | 22.7% | 26.1% | 33.8% |
| Divorced | 6.9% | 5.7% | 10.8% |
| Widowed | 4.8% | 4.5% | 5.6% |
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| Household Size | 2.96 | 3.09 | 2.60 |
| Households | 989 | 3,567 | 124,010,992 |
| Family Households | 846 | 2,979 | 80,755,759 |
| Married couple, w/children | 38.4% | 52.0% | 30.5% |
| Married couple, no children | 48.7% | 37.6% | 42.9% |
| Non Family Households | 143 | 588 | 43,255,233 |
| Single householder, w/children | 6.1% | 4.3% | 15.8% |
| Single householder, no children | 6.7% | 6.1% | 10.8% |