| | Chester, VA | Mahopac, NY | United States |
| Population | 22,512 | 8,573 | 329,725,481 |
| Female Population | 51.7% | 50.7% | 50.5% |
| Male Population | 48.3% | 49.3% | 49.5% |
| Median Age | 38.4 | 45.1 | 38.4 |
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| Population - 2010 | 19,918 | 7,602 | 309,327,143 |
| Population - 2000 | 17,890 | 8,478 | 285,036,114 |
| Population - 1990 | 14,986 | 7,755 | 251,960,433 |
| Pop. 2000 to Now | 31.2% | 2.5% | 15.6% |
| Pop. 1990 to Now | 56.6% | 12.0% | 30.8% |
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| Population Density | 1,704.3 | 1,624.0 | 93.4 |
| Land Area | 13.2 | 5.3 | 3,531,905.4 |
| Water Area | 0.1 | 1.2 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Chester, VA | Mahopac, NY | United States |
| Age 0 to 4 | 6.2% | 5.9% | 5.9% |
| Age 5 to 9 | 7.7% | 6.6% | 6.1% |
| Age 10 to 14 | 6.2% | 3.6% | 6.6% |
| Age 15 to 17 | 5.1% | 3.6% | 3.9% |
| Age 18 to 20 | 3.9% | 1.6% | 4.0% |
| Age 21 to 24 | 4.0% | 4.2% | 5.2% |
| Age 25 to 34 | 12.2% | 13.6% | 13.8% |
| Age 35 to 44 | 12.6% | 10.7% | 12.9% |
| Age 45 to 54 | 15.8% | 14.4% | 12.6% |
| Age 55 to 59 | 6.8% | 7.8% | 6.7% |
| Age 60 to 64 | 5.5% | 9.6% | 6.3% |
| Age 65 to 74 | 8.1% | 12.3% | 9.6% |
| Age 75 to 84 | 4.2% | 4.0% | 4.5% |
| Age 85 and over | 1.7% | 2.0% | 1.9% |
| space1 | | | |
| Race | | | |
| | Chester, VA | Mahopac, NY | United States |
| White | 59.3% | 85.3% | 59.4% |
| Black | 24.7% | 1.1% | 12.2% |
| Asian | 1.8% | 1.4% | 5.6% |
| Native American | 0.1% | 0.0% | 0.6% |
| Hawaiian, Pacific Islander | 0.7% | 0.0% | 0.2% |
| Other | 0.4% | 0.4% | 0.4% |
| Two or More Races | 3.8% | 1.3% | 3.2% |
| Hispanic | 9.1% | 10.5% | 18.4% |
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| Marriage & Family | | | |
| | Chester, VA | Mahopac, NY | United States |
| Married Population | 53.3% | 60.8% | 49.8% |
| Currently Married | 51.3% | 58.1% | 48.0% |
| Married but Separated | 2.0% | 2.7% | 1.8% |
| Single Population | 46.7% | 39.2% | 50.2% |
| Never Married | 32.4% | 25.3% | 33.8% |
| Divorced | 9.1% | 7.2% | 10.8% |
| Widowed | 5.2% | 6.7% | 5.6% |
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| Household Size | 2.63 | 2.68 | 2.60 |
| Households | 8,544 | 3,194 | 124,010,992 |
| Family Households | 6,200 | 2,324 | 80,755,759 |
| Married couple, w/children | 25.5% | 34.0% | 30.5% |
| Married couple, no children | 43.6% | 51.8% | 42.9% |
| Non Family Households | 2,344 | 870 | 43,255,233 |
| Single householder, w/children | 21.7% | 5.2% | 15.8% |
| Single householder, no children | 9.2% | 9.0% | 10.8% |