| | Decatur, NY | Rome, NY | United States |
| Population | 329 | 32,309 | 329,725,481 |
| Female Population | 42.9% | 49.6% | 50.5% |
| Male Population | 57.1% | 50.4% | 49.5% |
| Median Age | 50.3 | 39.9 | 38.4 |
| space3 | | | |
| Population - 2010 | 353 | 33,729 | 309,327,143 |
| Population - 2000 | 410 | 34,950 | 285,036,114 |
| Population - 1990 | 356 | 44,350 | 251,960,433 |
| Pop. 2000 to Now | -19.3% | -8.0% | 15.6% |
| Pop. 1990 to Now | -7.0% | -27.5% | 30.8% |
| space4 | | | |
| Population Density | 16.0 | 431.6 | 93.4 |
| Land Area | 20.6 | 74.9 | 3,531,905.4 |
| Water Area | 0.2 | 0.8 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Decatur, NY | Rome, NY | United States |
| Age 0 to 4 | 2.1% | 5.7% | 5.9% |
| Age 5 to 9 | 1.8% | 5.9% | 6.1% |
| Age 10 to 14 | 7.6% | 6.0% | 6.6% |
| Age 15 to 17 | 3.0% | 3.5% | 3.9% |
| Age 18 to 20 | 2.7% | 2.3% | 4.0% |
| Age 21 to 24 | 2.7% | 4.9% | 5.2% |
| Age 25 to 34 | 14.6% | 15.7% | 13.8% |
| Age 35 to 44 | 9.1% | 11.4% | 12.9% |
| Age 45 to 54 | 10.3% | 11.5% | 12.6% |
| Age 55 to 59 | 11.2% | 7.7% | 6.7% |
| Age 60 to 64 | 8.8% | 6.8% | 6.3% |
| Age 65 to 74 | 13.1% | 9.8% | 9.6% |
| Age 75 to 84 | 6.7% | 6.1% | 4.5% |
| Age 85 and over | 6.1% | 2.7% | 1.9% |
| space1 | | | |
| Race | | | |
| | Decatur, NY | Rome, NY | United States |
| White | 93.0% | 81.6% | 59.4% |
| Black | 2.4% | 5.8% | 12.2% |
| Asian | 0.0% | 1.4% | 5.6% |
| Native American | 0.0% | 0.1% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.0% | 0.1% | 0.4% |
| Two or More Races | 2.7% | 3.8% | 3.2% |
| Hispanic | 1.8% | 7.2% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Decatur, NY | Rome, NY | United States |
| Married Population | 56.4% | 43.6% | 49.8% |
| Currently Married | 55.3% | 39.9% | 48.0% |
| Married but Separated | 1.0% | 3.7% | 1.8% |
| Single Population | 43.6% | 56.4% | 50.2% |
| Never Married | 28.5% | 36.4% | 33.8% |
| Divorced | 8.6% | 11.7% | 10.8% |
| Widowed | 6.5% | 8.3% | 5.6% |
| space5 | | | |
| Household Size | 2.67 | 2.30 | 2.60 |
| Households | 123 | 13,006 | 124,010,992 |
| Family Households | 94 | 7,628 | 80,755,759 |
| Married couple, w/children | 26.6% | 20.9% | 30.5% |
| Married couple, no children | 58.5% | 41.5% | 42.9% |
| Non Family Households | 29 | 5,378 | 43,255,233 |
| Single householder, w/children | 4.3% | 25.6% | 15.8% |
| Single householder, no children | 10.6% | 12.0% | 10.8% |