| | Startup, WA | Brewster, WA | United States |
| Population | 549 | 2,329 | 329,725,481 |
| Female Population | 57.7% | 41.2% | 50.5% |
| Male Population | 42.3% | 58.8% | 49.5% |
| Median Age | 31.6 | 25.3 | 38.4 |
| space3 | | | |
| Population - 2010 | 776 | 2,371 | 309,327,143 |
| Population - 2000 | 817 | 2,189 | 285,036,114 |
| Population - 1990 | 578 | 1,633 | 251,960,433 |
| Pop. 2000 to Now | -9.8% | 9.2% | 15.6% |
| Pop. 1990 to Now | 27.5% | 46.4% | 30.8% |
| space4 | | | |
| Population Density | 133.5 | 2,021.7 | 93.4 |
| Land Area | 4.1 | 1.2 | 3,531,905.4 |
| Water Area | 0.1 | 0.0 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Startup, WA | Brewster, WA | United States |
| Age 0 to 4 | 0.7% | 11.5% | 5.9% |
| Age 5 to 9 | 11.7% | 13.9% | 6.1% |
| Age 10 to 14 | 2.4% | 7.9% | 6.6% |
| Age 15 to 17 | 0.0% | 4.3% | 3.9% |
| Age 18 to 20 | 0.9% | 3.7% | 4.0% |
| Age 21 to 24 | 6.0% | 7.3% | 5.2% |
| Age 25 to 34 | 32.1% | 18.8% | 13.8% |
| Age 35 to 44 | 20.2% | 9.3% | 12.9% |
| Age 45 to 54 | 5.6% | 7.2% | 12.6% |
| Age 55 to 59 | 4.7% | 4.9% | 6.7% |
| Age 60 to 64 | 8.7% | 3.4% | 6.3% |
| Age 65 to 74 | 6.9% | 5.7% | 9.6% |
| Age 75 to 84 | 0.0% | 1.7% | 4.5% |
| Age 85 and over | 0.0% | 0.4% | 1.9% |
| space1 | | | |
| Race | | | |
| | Startup, WA | Brewster, WA | United States |
| White | 64.8% | 14.8% | 59.4% |
| Black | 0.0% | 0.9% | 12.2% |
| Asian | 0.0% | 0.5% | 5.6% |
| Native American | 0.0% | 0.0% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.0% | 0.6% | 0.4% |
| Two or More Races | 7.5% | 0.6% | 3.2% |
| Hispanic | 27.7% | 82.5% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Startup, WA | Brewster, WA | United States |
| Married Population | 42.9% | 39.9% | 49.8% |
| Currently Married | 42.9% | 36.6% | 48.0% |
| Married but Separated | 0.0% | 3.2% | 1.8% |
| Single Population | 57.1% | 60.1% | 50.2% |
| Never Married | 22.9% | 47.7% | 33.8% |
| Divorced | 18.8% | 6.3% | 10.8% |
| Widowed | 15.4% | 6.2% | 5.6% |
| space5 | | | |
| Household Size | 2.07 | 3.17 | 2.60 |
| Households | 265 | 720 | 124,010,992 |
| Family Households | 158 | 503 | 80,755,759 |
| Married couple, w/children | 20.3% | 26.4% | 30.5% |
| Married couple, no children | 43.0% | 22.7% | 42.9% |
| Non Family Households | 107 | 217 | 43,255,233 |
| Single householder, w/children | 27.2% | 39.4% | 15.8% |
| Single householder, no children | 9.5% | 11.5% | 10.8% |