| | Northport, MI | Bellaire, MI | United States |
| Population | 401 | 969 | 329,725,481 |
| Female Population | 55.9% | 50.1% | 50.5% |
| Male Population | 44.1% | 50.0% | 49.5% |
| Median Age | 65.1 | 44.3 | 38.4 |
| space3 | | | |
| Population - 2010 | 526 | 1,082 | 309,327,143 |
| Population - 2000 | 648 | 1,164 | 285,036,114 |
| Population - 1990 | 605 | 1,104 | 251,960,433 |
| Pop. 2000 to Now | -19.0% | -8.3% | 15.6% |
| Pop. 1990 to Now | -13.2% | -3.3% | 30.8% |
| space4 | | | |
| Population Density | 243.3 | 518.7 | 93.4 |
| Land Area | 1.6 | 1.9 | 3,531,905.4 |
| Water Area | 0.0 | 0.1 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Northport, MI | Bellaire, MI | United States |
| Age 0 to 4 | 5.0% | 5.1% | 5.9% |
| Age 5 to 9 | 2.0% | 4.7% | 6.1% |
| Age 10 to 14 | 1.0% | 5.2% | 6.6% |
| Age 15 to 17 | 1.7% | 3.5% | 3.9% |
| Age 18 to 20 | 4.5% | 3.7% | 4.0% |
| Age 21 to 24 | 4.2% | 4.4% | 5.2% |
| Age 25 to 34 | 6.2% | 10.9% | 13.8% |
| Age 35 to 44 | 4.5% | 13.8% | 12.9% |
| Age 45 to 54 | 2.2% | 11.1% | 12.6% |
| Age 55 to 59 | 6.5% | 5.7% | 6.7% |
| Age 60 to 64 | 11.7% | 8.9% | 6.3% |
| Age 65 to 74 | 32.9% | 12.6% | 9.6% |
| Age 75 to 84 | 12.7% | 8.3% | 4.5% |
| Age 85 and over | 4.7% | 2.1% | 1.9% |
| space1 | | | |
| Race | | | |
| | Northport, MI | Bellaire, MI | United States |
| White | 92.0% | 91.4% | 59.4% |
| Black | 0.0% | 0.7% | 12.2% |
| Asian | 0.0% | 0.2% | 5.6% |
| Native American | 0.0% | 0.0% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.0% | 1.7% | 0.4% |
| Two or More Races | 0.7% | 3.7% | 3.2% |
| Hispanic | 7.2% | 2.3% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Northport, MI | Bellaire, MI | United States |
| Married Population | 59.1% | 40.9% | 49.8% |
| Currently Married | 59.1% | 39.0% | 48.0% |
| Married but Separated | 0.0% | 1.9% | 1.8% |
| Single Population | 40.9% | 59.1% | 50.2% |
| Never Married | 28.5% | 32.3% | 33.8% |
| Divorced | 7.3% | 19.3% | 10.8% |
| Widowed | 5.1% | 7.5% | 5.6% |
| space5 | | | |
| Household Size | 1.89 | 2.11 | 2.60 |
| Households | 208 | 443 | 124,010,992 |
| Family Households | 109 | 211 | 80,755,759 |
| Married couple, w/children | 24.8% | 28.0% | 30.5% |
| Married couple, no children | 69.7% | 44.6% | 42.9% |
| Non Family Households | 99 | 232 | 43,255,233 |
| Single householder, w/children | 0.0% | 18.0% | 15.8% |
| Single householder, no children | 5.5% | 9.5% | 10.8% |