| | Marcellus, NY | Westminster, CO | United States |
| Population | 6,105 | 115,535 | 329,725,481 |
| Female Population | 50.2% | 49.8% | 50.5% |
| Male Population | 49.8% | 50.2% | 49.5% |
| Median Age | 47.5 | 37.6 | 38.4 |
| space3 | | | |
| Population - 2010 | 6,233 | 106,479 | 309,327,143 |
| Population - 2000 | 6,319 | 100,940 | 285,036,114 |
| Population - 1990 | 6,465 | 74,625 | 251,960,433 |
| Pop. 2000 to Now | -4.7% | 14.0% | 15.6% |
| Pop. 1990 to Now | -6.9% | 54.2% | 30.8% |
| space4 | | | |
| Population Density | 188.2 | 3,658.4 | 93.4 |
| Land Area | 32.4 | 31.6 | 3,531,905.4 |
| Water Area | 0.1 | 2.3 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Marcellus, NY | Westminster, CO | United States |
| Age 0 to 4 | 3.4% | 4.9% | 5.9% |
| Age 5 to 9 | 3.8% | 5.9% | 6.1% |
| Age 10 to 14 | 6.4% | 5.8% | 6.6% |
| Age 15 to 17 | 6.5% | 3.6% | 3.9% |
| Age 18 to 20 | 2.8% | 3.7% | 4.0% |
| Age 21 to 24 | 2.7% | 5.1% | 5.2% |
| Age 25 to 34 | 9.1% | 16.8% | 13.8% |
| Age 35 to 44 | 11.1% | 14.3% | 12.9% |
| Age 45 to 54 | 14.9% | 12.3% | 12.6% |
| Age 55 to 59 | 8.7% | 6.9% | 6.7% |
| Age 60 to 64 | 8.1% | 6.6% | 6.3% |
| Age 65 to 74 | 13.4% | 8.8% | 9.6% |
| Age 75 to 84 | 6.9% | 3.6% | 4.5% |
| Age 85 and over | 2.2% | 1.6% | 1.9% |
| space1 | | | |
| Race | | | |
| | Marcellus, NY | Westminster, CO | United States |
| White | 94.6% | 66.0% | 59.4% |
| Black | 0.4% | 1.3% | 12.2% |
| Asian | 0.7% | 4.9% | 5.6% |
| Native American | 0.0% | 0.4% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.1% | 0.2% |
| Other | 0.4% | 0.4% | 0.4% |
| Two or More Races | 2.2% | 3.2% | 3.2% |
| Hispanic | 1.8% | 23.7% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Marcellus, NY | Westminster, CO | United States |
| Married Population | 58.4% | 50.6% | 49.8% |
| Currently Married | 57.1% | 49.3% | 48.0% |
| Married but Separated | 1.3% | 1.3% | 1.8% |
| Single Population | 41.6% | 49.4% | 50.2% |
| Never Married | 28.2% | 32.8% | 33.8% |
| Divorced | 9.3% | 12.4% | 10.8% |
| Widowed | 4.1% | 4.1% | 5.6% |
| space5 | | | |
| Household Size | 2.37 | 2.45 | 2.60 |
| Households | 2,580 | 46,968 | 124,010,992 |
| Family Households | 1,756 | 29,067 | 80,755,759 |
| Married couple, w/children | 25.8% | 30.3% | 30.5% |
| Married couple, no children | 56.4% | 45.4% | 42.9% |
| Non Family Households | 824 | 17,901 | 43,255,233 |
| Single householder, w/children | 13.3% | 14.4% | 15.8% |
| Single householder, no children | 4.5% | 9.9% | 10.8% |