| | Middleton, ID | Melba, ID | United States |
| Population | 9,091 | 652 | 329,725,481 |
| Female Population | 47.5% | 49.2% | 50.5% |
| Male Population | 52.5% | 50.8% | 49.5% |
| Median Age | 31.3 | 29.1 | 38.4 |
| space3 | | | |
| Population - 2010 | 5,531 | 507 | 309,327,143 |
| Population - 2000 | 2,978 | 439 | 285,036,114 |
| Population - 1990 | 1,851 | 252 | 251,960,433 |
| Pop. 2000 to Now | 199.6% | 26.0% | 15.6% |
| Pop. 1990 to Now | 382.0% | 119.4% | 30.8% |
| space4 | | | |
| Population Density | 1,679.8 | 1,630.0 | 93.4 |
| Land Area | 5.4 | 0.4 | 3,531,905.4 |
| Water Area | 0.0 | 0.0 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Middleton, ID | Melba, ID | United States |
| Age 0 to 4 | 9.9% | 8.0% | 5.9% |
| Age 5 to 9 | 6.2% | 9.5% | 6.1% |
| Age 10 to 14 | 11.0% | 12.9% | 6.6% |
| Age 15 to 17 | 5.7% | 3.1% | 3.9% |
| Age 18 to 20 | 4.3% | 7.5% | 4.0% |
| Age 21 to 24 | 4.6% | 4.8% | 5.2% |
| Age 25 to 34 | 13.5% | 12.0% | 13.8% |
| Age 35 to 44 | 14.8% | 16.6% | 12.9% |
| Age 45 to 54 | 8.2% | 6.6% | 12.6% |
| Age 55 to 59 | 5.5% | 4.9% | 6.7% |
| Age 60 to 64 | 4.3% | 4.8% | 6.3% |
| Age 65 to 74 | 8.9% | 5.5% | 9.6% |
| Age 75 to 84 | 2.4% | 2.1% | 4.5% |
| Age 85 and over | 0.7% | 1.8% | 1.9% |
| space1 | | | |
| Race | | | |
| | Middleton, ID | Melba, ID | United States |
| White | 75.5% | 70.7% | 59.4% |
| Black | 0.1% | 0.3% | 12.2% |
| Asian | 1.3% | 0.0% | 5.6% |
| Native American | 0.9% | 0.3% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.0% | 0.3% | 0.4% |
| Two or More Races | 5.5% | 2.5% | 3.2% |
| Hispanic | 16.7% | 25.9% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Middleton, ID | Melba, ID | United States |
| Married Population | 56.6% | 48.0% | 49.8% |
| Currently Married | 53.9% | 43.0% | 48.0% |
| Married but Separated | 2.7% | 5.1% | 1.8% |
| Single Population | 43.4% | 52.0% | 50.2% |
| Never Married | 27.2% | 35.0% | 33.8% |
| Divorced | 12.6% | 8.8% | 10.8% |
| Widowed | 3.6% | 8.2% | 5.6% |
| space5 | | | |
| Household Size | 3.04 | 3.08 | 2.60 |
| Households | 2,993 | 212 | 124,010,992 |
| Family Households | 2,223 | 142 | 80,755,759 |
| Married couple, w/children | 40.9% | 40.8% | 30.5% |
| Married couple, no children | 36.3% | 25.4% | 42.9% |
| Non Family Households | 770 | 70 | 43,255,233 |
| Single householder, w/children | 18.4% | 20.4% | 15.8% |
| Single householder, no children | 4.4% | 13.4% | 10.8% |