| | Hillcrest Heights, MD | Lihue, HI | United States |
| Population | 17,090 | 8,371 | 329,725,481 |
| Female Population | 55.2% | 52.2% | 50.5% |
| Male Population | 44.8% | 47.8% | 49.5% |
| Median Age | 36.9 | 45.2 | 38.4 |
| space3 | | | |
| Population - 2010 | 15,910 | 7,387 | 309,327,143 |
| Population - 2000 | 16,359 | 5,674 | 285,036,114 |
| Population - 1990 | 17,136 | 5,536 | 251,960,433 |
| Pop. 2000 to Now | -1.1% | 25.9% | 15.6% |
| Pop. 1990 to Now | -5.5% | 29.0% | 30.8% |
| space4 | | | |
| Population Density | 6,871.7 | 1,254.8 | 93.4 |
| Land Area | 2.5 | 6.7 | 3,531,905.4 |
| Water Area | 0.0 | 0.8 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Hillcrest Heights, MD | Lihue, HI | United States |
| Age 0 to 4 | 5.0% | 5.8% | 5.9% |
| Age 5 to 9 | 6.9% | 5.2% | 6.1% |
| Age 10 to 14 | 5.8% | 6.2% | 6.6% |
| Age 15 to 17 | 5.3% | 4.9% | 3.9% |
| Age 18 to 20 | 2.6% | 3.9% | 4.0% |
| Age 21 to 24 | 5.7% | 2.7% | 5.2% |
| Age 25 to 34 | 16.1% | 9.6% | 13.8% |
| Age 35 to 44 | 13.2% | 11.1% | 12.9% |
| Age 45 to 54 | 14.0% | 13.8% | 12.6% |
| Age 55 to 59 | 5.2% | 5.3% | 6.7% |
| Age 60 to 64 | 4.7% | 7.5% | 6.3% |
| Age 65 to 74 | 9.7% | 12.6% | 9.6% |
| Age 75 to 84 | 4.8% | 5.5% | 4.5% |
| Age 85 and over | 1.0% | 5.9% | 1.9% |
| space1 | | | |
| Race | | | |
| | Hillcrest Heights, MD | Lihue, HI | United States |
| White | 2.7% | 17.1% | 59.4% |
| Black | 87.7% | 1.9% | 12.2% |
| Asian | 0.0% | 42.1% | 5.6% |
| Native American | 0.0% | 0.6% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 4.9% | 0.2% |
| Other | 0.8% | 0.0% | 0.4% |
| Two or More Races | 1.8% | 18.7% | 3.2% |
| Hispanic | 7.0% | 14.8% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Hillcrest Heights, MD | Lihue, HI | United States |
| Married Population | 28.7% | 51.1% | 49.8% |
| Currently Married | 25.0% | 48.8% | 48.0% |
| Married but Separated | 3.7% | 2.3% | 1.8% |
| Single Population | 71.3% | 48.9% | 50.2% |
| Never Married | 55.0% | 32.0% | 33.8% |
| Divorced | 11.8% | 11.0% | 10.8% |
| Widowed | 4.5% | 5.9% | 5.6% |
| space5 | | | |
| Household Size | 2.35 | 3.15 | 2.60 |
| Households | 7,270 | 2,603 | 124,010,992 |
| Family Households | 3,648 | 1,741 | 80,755,759 |
| Married couple, w/children | 12.6% | 32.4% | 30.5% |
| Married couple, no children | 26.5% | 41.8% | 42.9% |
| Non Family Households | 3,622 | 862 | 43,255,233 |
| Single householder, w/children | 39.3% | 15.2% | 15.8% |
| Single householder, no children | 21.6% | 10.6% | 10.8% |