| | Lincoln, MA | Harvard, MA | United States |
| Population | 6,941 | 6,829 | 329,725,481 |
| Female Population | 50.5% | 41.2% | 50.5% |
| Male Population | 49.5% | 58.8% | 49.5% |
| Median Age | 41.9 | 42.5 | 38.4 |
| space3 | | | |
| Population - 2010 | 6,389 | 6,533 | 309,327,143 |
| Population - 2000 | 8,056 | 5,981 | 285,036,114 |
| Population - 1990 | 7,666 | 12,329 | 251,960,433 |
| Pop. 2000 to Now | -13.2% | 10.7% | 15.6% |
| Pop. 1990 to Now | -8.8% | -46.3% | 30.8% |
| space4 | | | |
| Population Density | 487.8 | 258.3 | 93.4 |
| Land Area | 14.2 | 26.4 | 3,531,905.4 |
| Water Area | 0.8 | 0.7 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Lincoln, MA | Harvard, MA | United States |
| Age 0 to 4 | 7.6% | 6.8% | 5.9% |
| Age 5 to 9 | 8.9% | 5.9% | 6.1% |
| Age 10 to 14 | 9.0% | 4.8% | 6.6% |
| Age 15 to 17 | 3.7% | 6.2% | 3.9% |
| Age 18 to 20 | 3.0% | 2.3% | 4.0% |
| Age 21 to 24 | 2.2% | 2.7% | 5.2% |
| Age 25 to 34 | 9.4% | 9.4% | 13.8% |
| Age 35 to 44 | 11.3% | 14.4% | 12.9% |
| Age 45 to 54 | 13.7% | 19.4% | 12.6% |
| Age 55 to 59 | 7.7% | 6.0% | 6.7% |
| Age 60 to 64 | 4.3% | 6.5% | 6.3% |
| Age 65 to 74 | 6.8% | 11.7% | 9.6% |
| Age 75 to 84 | 6.8% | 2.2% | 4.5% |
| Age 85 and over | 5.5% | 1.6% | 1.9% |
| space1 | | | |
| Race | | | |
| | Lincoln, MA | Harvard, MA | United States |
| White | 74.2% | 77.5% | 59.4% |
| Black | 1.0% | 8.0% | 12.2% |
| Asian | 6.8% | 3.5% | 5.6% |
| Native American | 0.0% | 0.3% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 1.1% | 0.6% | 0.4% |
| Two or More Races | 4.3% | 0.5% | 3.2% |
| Hispanic | 12.7% | 9.7% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Lincoln, MA | Harvard, MA | United States |
| Married Population | 69.4% | 56.3% | 49.8% |
| Currently Married | 69.4% | 55.1% | 48.0% |
| Married but Separated | 0.0% | 1.2% | 1.8% |
| Single Population | 30.6% | 43.7% | 50.2% |
| Never Married | 17.2% | 29.4% | 33.8% |
| Divorced | 6.7% | 10.9% | 10.8% |
| Widowed | 6.7% | 3.4% | 5.6% |
| space5 | | | |
| Household Size | 2.70 | 3.07 | 2.60 |
| Households | 2,566 | 1,849 | 124,010,992 |
| Family Households | 1,951 | 1,532 | 80,755,759 |
| Married couple, w/children | 45.3% | 44.7% | 30.5% |
| Married couple, no children | 43.1% | 44.7% | 42.9% |
| Non Family Households | 615 | 317 | 43,255,233 |
| Single householder, w/children | 10.1% | 5.7% | 15.8% |
| Single householder, no children | 1.6% | 4.8% | 10.8% |