| | Wilmington, OH | Bay City, MI | United States |
| Population | 12,523 | 32,824 | 329,725,481 |
| Female Population | 54.2% | 52.3% | 50.5% |
| Male Population | 45.8% | 47.7% | 49.5% |
| Median Age | 35.7 | 39 | 38.4 |
| space3 | | | |
| Population - 2010 | 12,542 | 34,879 | 309,327,143 |
| Population - 2000 | 11,921 | 36,817 | 285,036,114 |
| Population - 1990 | 11,199 | 38,936 | 251,960,433 |
| Pop. 2000 to Now | 4.0% | -11.9% | 15.6% |
| Pop. 1990 to Now | 10.7% | -16.7% | 30.8% |
| space4 | | | |
| Population Density | 1,150.0 | 3,228.8 | 93.4 |
| Land Area | 10.9 | 10.2 | 3,531,905.4 |
| Water Area | 0.0 | 1.0 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Wilmington, OH | Bay City, MI | United States |
| Age 0 to 4 | 7.3% | 4.8% | 5.9% |
| Age 5 to 9 | 6.1% | 6.1% | 6.1% |
| Age 10 to 14 | 6.1% | 6.4% | 6.6% |
| Age 15 to 17 | 3.0% | 4.3% | 3.9% |
| Age 18 to 20 | 7.7% | 3.8% | 4.0% |
| Age 21 to 24 | 7.6% | 5.6% | 5.2% |
| Age 25 to 34 | 12.0% | 13.5% | 13.8% |
| Age 35 to 44 | 9.3% | 13.4% | 12.9% |
| Age 45 to 54 | 10.8% | 13.0% | 12.6% |
| Age 55 to 59 | 6.0% | 6.9% | 6.7% |
| Age 60 to 64 | 6.6% | 7.7% | 6.3% |
| Age 65 to 74 | 9.2% | 8.7% | 9.6% |
| Age 75 to 84 | 5.6% | 3.8% | 4.5% |
| Age 85 and over | 2.7% | 2.0% | 1.9% |
| space1 | | | |
| Race | | | |
| | Wilmington, OH | Bay City, MI | United States |
| White | 87.1% | 83.6% | 59.4% |
| Black | 4.0% | 2.3% | 12.2% |
| Asian | 1.1% | 0.5% | 5.6% |
| Native American | 0.0% | 0.2% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.2% | 0.2% |
| Other | 0.5% | 0.0% | 0.4% |
| Two or More Races | 4.6% | 3.0% | 3.2% |
| Hispanic | 2.7% | 10.1% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Wilmington, OH | Bay City, MI | United States |
| Married Population | 39.5% | 38.1% | 49.8% |
| Currently Married | 37.2% | 36.5% | 48.0% |
| Married but Separated | 2.3% | 1.6% | 1.8% |
| Single Population | 60.5% | 61.9% | 50.2% |
| Never Married | 35.9% | 38.2% | 33.8% |
| Divorced | 15.3% | 17.3% | 10.8% |
| Widowed | 9.3% | 6.4% | 5.6% |
| space5 | | | |
| Household Size | 2.16 | 2.25 | 2.60 |
| Households | 5,298 | 14,417 | 124,010,992 |
| Family Households | 2,850 | 7,576 | 80,755,759 |
| Married couple, w/children | 21.3% | 21.3% | 30.5% |
| Married couple, no children | 39.7% | 38.8% | 42.9% |
| Non Family Households | 2,448 | 6,841 | 43,255,233 |
| Single householder, w/children | 26.9% | 28.0% | 15.8% |
| Single householder, no children | 12.1% | 11.9% | 10.8% |