| | Monterey, MA | Middlefield, OH | United States |
| Population | 793 | 2,738 | 329,725,481 |
| Female Population | 52.6% | 57.3% | 50.5% |
| Male Population | 47.4% | 42.7% | 49.5% |
| Median Age | 64.9 | 48.9 | 38.4 |
| space3 | | | |
| Population - 2010 | 953 | 2,689 | 309,327,143 |
| Population - 2000 | 934 | 2,233 | 285,036,114 |
| Population - 1990 | 805 | 1,898 | 251,960,433 |
| Pop. 2000 to Now | -1.7% | 20.5% | 15.6% |
| Pop. 1990 to Now | 14.0% | 41.7% | 30.8% |
| space4 | | | |
| Population Density | 30.0 | 900.4 | 93.4 |
| Land Area | 26.4 | 3.0 | 3,531,905.4 |
| Water Area | 1.0 | 0.0 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Monterey, MA | Middlefield, OH | United States |
| Age 0 to 4 | 1.1% | 1.1% | 5.9% |
| Age 5 to 9 | 2.0% | 4.6% | 6.1% |
| Age 10 to 14 | 4.9% | 4.2% | 6.6% |
| Age 15 to 17 | 2.1% | 2.9% | 3.9% |
| Age 18 to 20 | 2.9% | 6.0% | 4.0% |
| Age 21 to 24 | 4.4% | 6.0% | 5.2% |
| Age 25 to 34 | 2.3% | 9.9% | 13.8% |
| Age 35 to 44 | 5.8% | 8.7% | 12.9% |
| Age 45 to 54 | 8.7% | 13.5% | 12.6% |
| Age 55 to 59 | 8.3% | 6.4% | 6.7% |
| Age 60 to 64 | 7.6% | 7.6% | 6.3% |
| Age 65 to 74 | 17.9% | 16.8% | 9.6% |
| Age 75 to 84 | 12.2% | 8.2% | 4.5% |
| Age 85 and over | 19.7% | 4.1% | 1.9% |
| space1 | | | |
| Race | | | |
| | Monterey, MA | Middlefield, OH | United States |
| White | 97.7% | 97.1% | 59.4% |
| Black | 0.0% | 2.1% | 12.2% |
| Asian | 0.0% | 0.1% | 5.6% |
| Native American | 0.0% | 0.0% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.0% | 0.6% | 0.4% |
| Two or More Races | 0.0% | 0.0% | 3.2% |
| Hispanic | 2.3% | 0.1% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Monterey, MA | Middlefield, OH | United States |
| Married Population | 67.8% | 36.3% | 49.8% |
| Currently Married | 67.8% | 35.9% | 48.0% |
| Married but Separated | 0.0% | 0.4% | 1.8% |
| Single Population | 32.2% | 63.7% | 50.2% |
| Never Married | 16.7% | 40.2% | 33.8% |
| Divorced | 8.5% | 13.0% | 10.8% |
| Widowed | 7.0% | 10.5% | 5.6% |
| space5 | | | |
| Household Size | 2.05 | 2.06 | 2.60 |
| Households | 369 | 1,284 | 124,010,992 |
| Family Households | 269 | 575 | 80,755,759 |
| Married couple, w/children | 20.4% | 26.1% | 30.5% |
| Married couple, no children | 74.0% | 49.2% | 42.9% |
| Non Family Households | 100 | 709 | 43,255,233 |
| Single householder, w/children | 0.0% | 14.1% | 15.8% |
| Single householder, no children | 5.6% | 10.6% | 10.8% |