| | Mamaroneck, NY | Yonkers, NY | United States |
| Population | 31,381 | 209,730 | 329,725,481 |
| Female Population | 47.9% | 51.4% | 50.5% |
| Male Population | 52.1% | 48.6% | 49.5% |
| Median Age | 38.9 | 39.1 | 38.4 |
| space3 | | | |
| Population - 2010 | 29,228 | 196,510 | 309,327,143 |
| Population - 2000 | 28,967 | 196,086 | 285,036,114 |
| Population - 1990 | 27,706 | 188,082 | 251,960,433 |
| Pop. 2000 to Now | 1.3% | 2.0% | 15.6% |
| Pop. 1990 to Now | 5.9% | 6.4% | 30.8% |
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| Population Density | 4,716.1 | 11,643.9 | 93.4 |
| Land Area | 6.7 | 18.0 | 3,531,905.4 |
| Water Area | 7.4 | 2.3 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Mamaroneck, NY | Yonkers, NY | United States |
| Age 0 to 4 | 6.4% | 6.1% | 5.9% |
| Age 5 to 9 | 9.1% | 5.3% | 6.1% |
| Age 10 to 14 | 8.6% | 6.1% | 6.6% |
| Age 15 to 17 | 3.9% | 3.8% | 3.9% |
| Age 18 to 20 | 2.9% | 4.1% | 4.0% |
| Age 21 to 24 | 2.5% | 4.8% | 5.2% |
| Age 25 to 34 | 10.4% | 14.3% | 13.8% |
| Age 35 to 44 | 16.4% | 12.9% | 12.9% |
| Age 45 to 54 | 14.4% | 12.8% | 12.6% |
| Age 55 to 59 | 5.7% | 6.8% | 6.7% |
| Age 60 to 64 | 6.4% | 6.2% | 6.3% |
| Age 65 to 74 | 7.5% | 9.1% | 9.6% |
| Age 75 to 84 | 3.7% | 5.1% | 4.5% |
| Age 85 and over | 2.2% | 2.6% | 1.9% |
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| Race | | | |
| | Mamaroneck, NY | Yonkers, NY | United States |
| White | 72.2% | 35.4% | 59.4% |
| Black | 2.6% | 15.6% | 12.2% |
| Asian | 4.7% | 5.7% | 5.6% |
| Native American | 0.0% | 0.3% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 1.0% | 1.2% | 0.4% |
| Two or More Races | 2.2% | 1.8% | 3.2% |
| Hispanic | 17.4% | 40.0% | 18.4% |
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| Marriage & Family | | | |
| | Mamaroneck, NY | Yonkers, NY | United States |
| Married Population | 60.5% | 46.2% | 49.8% |
| Currently Married | 57.3% | 43.6% | 48.0% |
| Married but Separated | 3.2% | 2.6% | 1.8% |
| Single Population | 39.5% | 53.8% | 50.2% |
| Never Married | 28.7% | 38.2% | 33.8% |
| Divorced | 6.1% | 9.3% | 10.8% |
| Widowed | 4.7% | 6.3% | 5.6% |
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| Household Size | 2.95 | 2.55 | 2.60 |
| Households | 10,519 | 80,936 | 124,010,992 |
| Family Households | 7,944 | 51,188 | 80,755,759 |
| Married couple, w/children | 46.4% | 29.0% | 30.5% |
| Married couple, no children | 37.2% | 36.0% | 42.9% |
| Non Family Households | 2,575 | 29,748 | 43,255,233 |
| Single householder, w/children | 9.4% | 18.7% | 15.8% |
| Single householder, no children | 7.0% | 16.3% | 10.8% |