| | Manhattan, NY | Boston, MA | United States |
| Population | 1,669,127 | 672,814 | 329,725,481 |
| Female Population | 52.7% | 51.9% | 50.8% |
| Male Population | 47.3% | 48.1% | 49.2% |
| Median Age | 37.1 | 32 | 37.8 |
| space3 | | | |
| Population - 2010 | 1,589,041 | 621,053 | 309,327,143 |
| Population - 2000 | 1,537,195 | 589,141 | 285,036,114 |
| Population - 1990 | 1,487,536 | 574,283 | 251,960,433 |
| Pop. 2000 to Now | 4.9% | 17.4% | 15.6% |
| Pop. 1990 to Now | 8.4% | 20.4% | 30.8% |
| space4 | | | |
| Population Density | 70,611.5 | 14,306.7 | 93.3 |
| Land Area | 22.8 | 48.3 | 3,531,905.4 |
| Water Area | 10.8 | 41.3 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Manhattan, NY | Boston, MA | United States |
| Age 0 to 4 | 5.0% | 5.2% | 6.2% |
| Age 5 to 9 | 3.8% | 4.3% | 6.4% |
| Age 10 to 14 | 3.6% | 4.1% | 6.5% |
| Age 15 to 17 | 2.1% | 2.7% | 3.9% |
| Age 18 to 20 | 3.3% | 7.1% | 4.1% |
| Age 21 to 24 | 6.1% | 8.3% | 5.6% |
| Age 25 to 34 | 22.6% | 23.8% | 13.7% |
| Age 35 to 44 | 14.4% | 12.5% | 12.7% |
| Age 45 to 54 | 12.5% | 11.1% | 13.4% |
| Age 55 to 59 | 5.7% | 5.3% | 6.7% |
| Age 60 to 64 | 5.5% | 4.6% | 6.0% |
| Age 65 to 74 | 8.4% | 6.2% | 8.6% |
| Age 75 to 84 | 4.5% | 3.2% | 4.4% |
| Age 85 and over | 2.3% | 1.5% | 1.9% |
| space1 | | | |
| Race | | | |
| | Manhattan, NY | Boston, MA | United States |
| White | 46.8% | 44.9% | 61.5% |
| Black | 12.5% | 22.7% | 12.3% |
| Asian | 11.9% | 9.4% | 5.3% |
| Native American | 0.1% | 0.2% | 0.7% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.4% | 1.0% | 0.2% |
| Two or More Races | 2.2% | 2.4% | 2.3% |
| Hispanic | 26.1% | 19.4% | 17.6% |
| space2 | | | |
| Marriage & Family | | | |
| | Manhattan, NY | Boston, MA | United States |
| Married Population | 36.8% | 32.6% | 50.2% |
| Currently Married | 34.1% | 29.7% | 48.2% |
| Married but Separated | 2.6% | 2.8% | 2.0% |
| Single Population | 63.2% | 67.4% | 49.8% |
| Never Married | 50.0% | 55.9% | 33.1% |
| Divorced | 8.4% | 7.5% | 10.9% |
| Widowed | 4.8% | 4.1% | 5.8% |
| space5 | | | |
| Household Size | 2.10 | 2.36 | 2.63 |
| Households | 758,345 | 263,229 | 118,825,921 |
| Family Households | 320,700 | 126,885 | 78,298,703 |
| Married couple, w/children | 25.5% | 22.6% | 31.1% |
| Married couple, no children | 40.8% | 34.4% | 42.3% |
| Non Family Households | 437,645 | 136,344 | 40,527,218 |
| Single householder, w/children | 16.8% | 24.2% | 16.3% |
| Single householder, no children | 16.9% | 18.7% | 10.3% |