| | Kapaa, HI | Kahuku, HI | United States |
| Population | 11,516 | 2,371 | 329,725,481 |
| Female Population | 47.5% | 52.9% | 50.5% |
| Male Population | 52.5% | 47.2% | 49.5% |
| Median Age | 44.6 | 32.7 | 38.4 |
| space3 | | | |
| Population - 2010 | 10,060 | 2,458 | 309,327,143 |
| Population - 2000 | 9,472 | 2,097 | 285,036,114 |
| Population - 1990 | 8,149 | 2,063 | 251,960,433 |
| Pop. 2000 to Now | 12.2% | 9.1% | 15.6% |
| Pop. 1990 to Now | 30.4% | 10.9% | 30.8% |
| space4 | | | |
| Population Density | 1,147.9 | 2,462.1 | 93.4 |
| Land Area | 10.0 | 1.0 | 3,531,905.4 |
| Water Area | 0.3 | 1.3 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Kapaa, HI | Kahuku, HI | United States |
| Age 0 to 4 | 4.9% | 11.0% | 5.9% |
| Age 5 to 9 | 7.5% | 9.6% | 6.1% |
| Age 10 to 14 | 3.7% | 10.3% | 6.6% |
| Age 15 to 17 | 2.6% | 4.1% | 3.9% |
| Age 18 to 20 | 1.2% | 2.0% | 4.0% |
| Age 21 to 24 | 3.4% | 6.2% | 5.2% |
| Age 25 to 34 | 10.3% | 10.2% | 13.8% |
| Age 35 to 44 | 17.0% | 14.5% | 12.9% |
| Age 45 to 54 | 16.7% | 8.8% | 12.6% |
| Age 55 to 59 | 5.5% | 6.7% | 6.7% |
| Age 60 to 64 | 7.5% | 4.7% | 6.3% |
| Age 65 to 74 | 11.5% | 7.1% | 9.6% |
| Age 75 to 84 | 6.3% | 3.5% | 4.5% |
| Age 85 and over | 1.9% | 1.4% | 1.9% |
| space1 | | | |
| Race | | | |
| | Kapaa, HI | Kahuku, HI | United States |
| White | 34.7% | 10.4% | 59.4% |
| Black | 1.0% | 2.3% | 12.2% |
| Asian | 29.8% | 14.5% | 5.6% |
| Native American | 0.0% | 0.0% | 0.6% |
| Hawaiian, Pacific Islander | 6.5% | 35.7% | 0.2% |
| Other | 0.3% | 0.0% | 0.4% |
| Two or More Races | 19.2% | 26.3% | 3.2% |
| Hispanic | 8.7% | 10.9% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Kapaa, HI | Kahuku, HI | United States |
| Married Population | 47.5% | 54.3% | 49.8% |
| Currently Married | 47.3% | 54.1% | 48.0% |
| Married but Separated | 0.2% | 0.2% | 1.8% |
| Single Population | 52.5% | 45.7% | 50.2% |
| Never Married | 34.0% | 31.2% | 33.8% |
| Divorced | 13.1% | 9.5% | 10.8% |
| Widowed | 5.3% | 5.0% | 5.6% |
| space5 | | | |
| Household Size | 3.14 | 4.04 | 2.60 |
| Households | 3,638 | 583 | 124,010,992 |
| Family Households | 2,485 | 464 | 80,755,759 |
| Married couple, w/children | 14.9% | 35.1% | 30.5% |
| Married couple, no children | 53.1% | 28.9% | 42.9% |
| Non Family Households | 1,153 | 119 | 43,255,233 |
| Single householder, w/children | 18.1% | 27.6% | 15.8% |
| Single householder, no children | 13.8% | 8.4% | 10.8% |