| | Westwood, MA | Needham, MA | United States |
| Population | 16,066 | 31,808 | 329,725,481 |
| Female Population | 51.6% | 53.1% | 50.5% |
| Male Population | 48.4% | 46.9% | 49.5% |
| Median Age | 44.4 | 43.4 | 38.4 |
| space3 | | | |
| Population - 2010 | 14,655 | 29,170 | 309,327,143 |
| Population - 2000 | 14,117 | 28,911 | 285,036,114 |
| Population - 1990 | 12,557 | 27,557 | 251,960,433 |
| Pop. 2000 to Now | 16.1% | 9.1% | 15.6% |
| Pop. 1990 to Now | 30.5% | 14.4% | 30.8% |
| space4 | | | |
| Population Density | 1,476.4 | 2,589.0 | 93.4 |
| Land Area | 10.9 | 12.3 | 3,531,905.4 |
| Water Area | 0.3 | 0.4 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Westwood, MA | Needham, MA | United States |
| Age 0 to 4 | 5.7% | 4.9% | 5.9% |
| Age 5 to 9 | 8.2% | 8.5% | 6.1% |
| Age 10 to 14 | 6.5% | 9.0% | 6.6% |
| Age 15 to 17 | 5.2% | 5.3% | 3.9% |
| Age 18 to 20 | 3.1% | 3.0% | 4.0% |
| Age 21 to 24 | 4.3% | 3.3% | 5.2% |
| Age 25 to 34 | 7.8% | 4.9% | 13.8% |
| Age 35 to 44 | 10.2% | 13.8% | 12.9% |
| Age 45 to 54 | 14.8% | 14.2% | 12.6% |
| Age 55 to 59 | 9.2% | 7.9% | 6.7% |
| Age 60 to 64 | 6.7% | 6.5% | 6.3% |
| Age 65 to 74 | 6.6% | 9.7% | 9.6% |
| Age 75 to 84 | 7.3% | 4.9% | 4.5% |
| Age 85 and over | 4.6% | 4.0% | 1.9% |
| space1 | | | |
| Race | | | |
| | Westwood, MA | Needham, MA | United States |
| White | 78.3% | 81.6% | 59.4% |
| Black | 2.9% | 2.3% | 12.2% |
| Asian | 11.8% | 9.3% | 5.6% |
| Native American | 0.0% | 0.1% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.5% | 0.0% | 0.4% |
| Two or More Races | 3.0% | 2.6% | 3.2% |
| Hispanic | 3.4% | 4.2% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Westwood, MA | Needham, MA | United States |
| Married Population | 64.7% | 67.3% | 49.8% |
| Currently Married | 63.8% | 66.5% | 48.0% |
| Married but Separated | 0.9% | 0.8% | 1.8% |
| Single Population | 35.3% | 32.7% | 50.2% |
| Never Married | 24.0% | 22.0% | 33.8% |
| Divorced | 5.3% | 6.0% | 10.8% |
| Widowed | 6.1% | 4.7% | 5.6% |
| space5 | | | |
| Household Size | 2.94 | 2.76 | 2.60 |
| Households | 5,424 | 11,260 | 124,010,992 |
| Family Households | 4,389 | 9,005 | 80,755,759 |
| Married couple, w/children | 42.7% | 46.5% | 30.5% |
| Married couple, no children | 46.8% | 42.2% | 42.9% |
| Non Family Households | 1,035 | 2,255 | 43,255,233 |
| Single householder, w/children | 3.8% | 6.2% | 15.8% |
| Single householder, no children | 6.7% | 5.1% | 10.8% |