| | Callahan, FL | Melbourne, FL | United States |
| Population | 1,637 | 83,500 | 329,725,481 |
| Female Population | 58.1% | 51.8% | 50.5% |
| Male Population | 41.9% | 48.2% | 49.5% |
| Median Age | 38.1 | 42.4 | 38.4 |
| space3 | | | |
| Population - 2010 | 1,108 | 76,371 | 309,327,143 |
| Population - 2000 | 962 | 71,382 | 285,036,114 |
| Population - 1990 | 946 | 59,646 | 251,960,433 |
| Pop. 2000 to Now | 44.3% | 16.8% | 15.6% |
| Pop. 1990 to Now | 46.7% | 39.8% | 30.8% |
| space4 | | | |
| Population Density | 1,170.1 | 1,896.0 | 93.4 |
| Land Area | 1.4 | 44.0 | 3,531,905.4 |
| Water Area | 0.0 | 5.8 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Callahan, FL | Melbourne, FL | United States |
| Age 0 to 4 | 4.1% | 4.7% | 5.9% |
| Age 5 to 9 | 4.5% | 4.6% | 6.1% |
| Age 10 to 14 | 7.6% | 5.6% | 6.6% |
| Age 15 to 17 | 4.5% | 3.2% | 3.9% |
| Age 18 to 20 | 5.8% | 4.0% | 4.0% |
| Age 21 to 24 | 3.6% | 5.2% | 5.2% |
| Age 25 to 34 | 14.8% | 14.7% | 13.8% |
| Age 35 to 44 | 12.4% | 10.4% | 12.9% |
| Age 45 to 54 | 12.2% | 11.8% | 12.6% |
| Age 55 to 59 | 4.5% | 7.4% | 6.7% |
| Age 60 to 64 | 5.6% | 6.9% | 6.3% |
| Age 65 to 74 | 14.8% | 11.9% | 9.6% |
| Age 75 to 84 | 4.1% | 5.8% | 4.5% |
| Age 85 and over | 1.6% | 3.9% | 1.9% |
| space1 | | | |
| Race | | | |
| | Callahan, FL | Melbourne, FL | United States |
| White | 77.2% | 69.2% | 59.4% |
| Black | 16.9% | 9.6% | 12.2% |
| Asian | 2.4% | 4.0% | 5.6% |
| Native American | 0.0% | 0.1% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.2% | 0.2% |
| Other | 0.0% | 0.5% | 0.4% |
| Two or More Races | 0.8% | 4.1% | 3.2% |
| Hispanic | 2.7% | 12.4% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Callahan, FL | Melbourne, FL | United States |
| Married Population | 45.2% | 43.7% | 49.8% |
| Currently Married | 41.7% | 41.9% | 48.0% |
| Married but Separated | 3.5% | 1.7% | 1.8% |
| Single Population | 54.8% | 56.3% | 50.2% |
| Never Married | 29.7% | 33.3% | 33.8% |
| Divorced | 13.8% | 15.0% | 10.8% |
| Widowed | 11.4% | 8.0% | 5.6% |
| space5 | | | |
| Household Size | 2.60 | 2.35 | 2.60 |
| Households | 630 | 34,473 | 124,010,992 |
| Family Households | 448 | 18,851 | 80,755,759 |
| Married couple, w/children | 26.3% | 24.4% | 30.5% |
| Married couple, no children | 31.9% | 46.0% | 42.9% |
| Non Family Households | 182 | 15,622 | 43,255,233 |
| Single householder, w/children | 21.4% | 16.5% | 15.8% |
| Single householder, no children | 20.3% | 13.1% | 10.8% |