| | Boxborough, MA | Marlborough, MA | United States |
| Population | 5,471 | 41,505 | 329,725,481 |
| Female Population | 52.5% | 51.3% | 50.5% |
| Male Population | 47.5% | 48.7% | 49.5% |
| Median Age | 43.4 | 39.2 | 38.4 |
| space3 | | | |
| Population - 2010 | 5,027 | 38,584 | 309,327,143 |
| Population - 2000 | 4,868 | 36,255 | 285,036,114 |
| Population - 1990 | 3,343 | 31,813 | 251,960,433 |
| Pop. 2000 to Now | 18.2% | 8.4% | 15.6% |
| Pop. 1990 to Now | 72.1% | 23.5% | 30.8% |
| space4 | | | |
| Population Density | 531.9 | 1,989.7 | 93.4 |
| Land Area | 10.3 | 20.9 | 3,531,905.4 |
| Water Area | 0.1 | 1.2 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Boxborough, MA | Marlborough, MA | United States |
| Age 0 to 4 | 2.7% | 6.6% | 5.9% |
| Age 5 to 9 | 6.1% | 5.5% | 6.1% |
| Age 10 to 14 | 7.3% | 5.0% | 6.6% |
| Age 15 to 17 | 4.7% | 2.6% | 3.9% |
| Age 18 to 20 | 7.7% | 2.3% | 4.0% |
| Age 21 to 24 | 3.1% | 4.6% | 5.2% |
| Age 25 to 34 | 7.9% | 16.4% | 13.8% |
| Age 35 to 44 | 13.3% | 14.4% | 12.9% |
| Age 45 to 54 | 14.6% | 13.3% | 12.6% |
| Age 55 to 59 | 13.8% | 8.1% | 6.7% |
| Age 60 to 64 | 6.9% | 6.9% | 6.3% |
| Age 65 to 74 | 7.5% | 8.6% | 9.6% |
| Age 75 to 84 | 3.4% | 3.8% | 4.5% |
| Age 85 and over | 1.1% | 1.8% | 1.9% |
| space1 | | | |
| Race | | | |
| | Boxborough, MA | Marlborough, MA | United States |
| White | 68.9% | 64.4% | 59.4% |
| Black | 6.7% | 3.4% | 12.2% |
| Asian | 18.6% | 5.2% | 5.6% |
| Native American | 0.0% | 0.0% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.0% | 4.1% | 0.4% |
| Two or More Races | 2.5% | 6.6% | 3.2% |
| Hispanic | 3.3% | 16.2% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Boxborough, MA | Marlborough, MA | United States |
| Married Population | 60.0% | 52.0% | 49.8% |
| Currently Married | 59.6% | 50.1% | 48.0% |
| Married but Separated | 0.4% | 2.0% | 1.8% |
| Single Population | 40.0% | 48.0% | 50.2% |
| Never Married | 29.4% | 33.1% | 33.8% |
| Divorced | 7.4% | 10.9% | 10.8% |
| Widowed | 3.2% | 4.0% | 5.6% |
| space5 | | | |
| Household Size | 2.51 | 2.39 | 2.60 |
| Households | 2,180 | 17,147 | 124,010,992 |
| Family Households | 1,398 | 10,313 | 80,755,759 |
| Married couple, w/children | 42.8% | 33.3% | 30.5% |
| Married couple, no children | 52.0% | 42.6% | 42.9% |
| Non Family Households | 782 | 6,834 | 43,255,233 |
| Single householder, w/children | 4.0% | 12.3% | 15.8% |
| Single householder, no children | 1.2% | 11.7% | 10.8% |