| | Seffner, FL | Oak Harbor, WA | United States |
| Population | 8,484 | 24,267 | 329,725,481 |
| Female Population | 51.0% | 52.7% | 50.5% |
| Male Population | 49.0% | 47.3% | 49.5% |
| Median Age | 39.3 | 31.1 | 38.4 |
| space3 | | | |
| Population - 2010 | 7,480 | 22,212 | 309,327,143 |
| Population - 2000 | 5,467 | 19,795 | 285,036,114 |
| Population - 1990 | 5,371 | 17,176 | 251,960,433 |
| Pop. 2000 to Now | 65.4% | 19.4% | 15.6% |
| Pop. 1990 to Now | 68.4% | 37.7% | 30.8% |
| space4 | | | |
| Population Density | 2,352.1 | 2,522.8 | 93.4 |
| Land Area | 3.6 | 9.6 | 3,531,905.4 |
| Water Area | 0.2 | 0.0 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Seffner, FL | Oak Harbor, WA | United States |
| Age 0 to 4 | 9.7% | 10.8% | 5.9% |
| Age 5 to 9 | 5.6% | 7.1% | 6.1% |
| Age 10 to 14 | 6.5% | 7.9% | 6.6% |
| Age 15 to 17 | 4.8% | 2.8% | 3.9% |
| Age 18 to 20 | 2.5% | 2.4% | 4.0% |
| Age 21 to 24 | 5.6% | 6.2% | 5.2% |
| Age 25 to 34 | 9.9% | 19.6% | 13.8% |
| Age 35 to 44 | 14.3% | 16.1% | 12.9% |
| Age 45 to 54 | 14.1% | 6.7% | 12.6% |
| Age 55 to 59 | 6.5% | 3.8% | 6.7% |
| Age 60 to 64 | 7.4% | 4.2% | 6.3% |
| Age 65 to 74 | 8.8% | 7.3% | 9.6% |
| Age 75 to 84 | 3.4% | 3.2% | 4.5% |
| Age 85 and over | 0.8% | 1.9% | 1.9% |
| space1 | | | |
| Race | | | |
| | Seffner, FL | Oak Harbor, WA | United States |
| White | 55.3% | 59.7% | 59.4% |
| Black | 15.3% | 5.2% | 12.2% |
| Asian | 0.4% | 8.7% | 5.6% |
| Native American | 0.1% | 1.3% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.5% | 0.2% |
| Other | 0.0% | 0.4% | 0.4% |
| Two or More Races | 2.8% | 8.1% | 3.2% |
| Hispanic | 26.1% | 16.1% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Seffner, FL | Oak Harbor, WA | United States |
| Married Population | 52.1% | 58.7% | 49.8% |
| Currently Married | 50.5% | 56.8% | 48.0% |
| Married but Separated | 1.6% | 1.9% | 1.8% |
| Single Population | 47.9% | 41.3% | 50.2% |
| Never Married | 31.5% | 25.0% | 33.8% |
| Divorced | 12.1% | 11.2% | 10.8% |
| Widowed | 4.4% | 5.1% | 5.6% |
| space5 | | | |
| Household Size | 3.07 | 2.52 | 2.60 |
| Households | 2,746 | 9,593 | 124,010,992 |
| Family Households | 2,122 | 6,346 | 80,755,759 |
| Married couple, w/children | 28.2% | 38.8% | 30.5% |
| Married couple, no children | 47.2% | 38.3% | 42.9% |
| Non Family Households | 624 | 3,247 | 43,255,233 |
| Single householder, w/children | 15.7% | 15.8% | 15.8% |
| Single householder, no children | 8.9% | 7.1% | 10.8% |