| | Kahului, HI | Duvall, WA | United States |
| Population | 27,938 | 8,007 | 329,725,481 |
| Female Population | 50.4% | 52.7% | 50.5% |
| Male Population | 49.7% | 47.3% | 49.5% |
| Median Age | 40.8 | 37 | 38.4 |
| space3 | | | |
| Population - 2010 | 24,712 | 6,744 | 309,327,143 |
| Population - 2000 | 20,146 | 4,616 | 285,036,114 |
| Population - 1990 | 16,889 | 2,770 | 251,960,433 |
| Pop. 2000 to Now | 56.1% | 76.8% | 15.6% |
| Pop. 1990 to Now | 86.1% | 194.6% | 30.8% |
| space4 | | | |
| Population Density | 1,942.0 | 3,265.5 | 93.4 |
| Land Area | 14.4 | 2.5 | 3,531,905.4 |
| Water Area | 1.6 | 0.0 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Kahului, HI | Duvall, WA | United States |
| Age 0 to 4 | 4.1% | 6.4% | 5.9% |
| Age 5 to 9 | 6.2% | 9.4% | 6.1% |
| Age 10 to 14 | 7.0% | 8.7% | 6.6% |
| Age 15 to 17 | 3.8% | 4.9% | 3.9% |
| Age 18 to 20 | 2.9% | 2.5% | 4.0% |
| Age 21 to 24 | 5.1% | 4.1% | 5.2% |
| Age 25 to 34 | 12.8% | 9.7% | 13.8% |
| Age 35 to 44 | 13.4% | 19.0% | 12.9% |
| Age 45 to 54 | 12.8% | 19.8% | 12.6% |
| Age 55 to 59 | 7.6% | 6.5% | 6.7% |
| Age 60 to 64 | 6.5% | 3.5% | 6.3% |
| Age 65 to 74 | 8.9% | 4.3% | 9.6% |
| Age 75 to 84 | 6.8% | 1.0% | 4.5% |
| Age 85 and over | 2.2% | 0.2% | 1.9% |
| space1 | | | |
| Race | | | |
| | Kahului, HI | Duvall, WA | United States |
| White | 9.0% | 77.1% | 59.4% |
| Black | 1.0% | 0.6% | 12.2% |
| Asian | 54.6% | 8.8% | 5.6% |
| Native American | 0.1% | 0.0% | 0.6% |
| Hawaiian, Pacific Islander | 11.8% | 0.0% | 0.2% |
| Other | 0.1% | 0.0% | 0.4% |
| Two or More Races | 14.3% | 2.1% | 3.2% |
| Hispanic | 9.2% | 11.4% | 18.4% |
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| Marriage & Family | | | |
| | Kahului, HI | Duvall, WA | United States |
| Married Population | 48.0% | 67.0% | 49.8% |
| Currently Married | 46.4% | 64.4% | 48.0% |
| Married but Separated | 1.5% | 2.6% | 1.8% |
| Single Population | 52.0% | 33.0% | 50.2% |
| Never Married | 35.0% | 21.9% | 33.8% |
| Divorced | 9.3% | 7.8% | 10.8% |
| Widowed | 7.8% | 3.2% | 5.6% |
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| Household Size | 3.33 | 2.94 | 2.60 |
| Households | 7,923 | 2,722 | 124,010,992 |
| Family Households | 6,131 | 2,221 | 80,755,759 |
| Married couple, w/children | 34.7% | 51.7% | 30.5% |
| Married couple, no children | 32.5% | 34.1% | 42.9% |
| Non Family Households | 1,792 | 501 | 43,255,233 |
| Single householder, w/children | 14.5% | 7.0% | 15.8% |
| Single householder, no children | 18.3% | 7.2% | 10.8% |