| | Poolesville, MD | Carpinteria, CA | United States |
| Population | 5,666 | 13,289 | 329,725,481 |
| Female Population | 50.6% | 49.2% | 50.5% |
| Male Population | 49.4% | 50.8% | 49.5% |
| Median Age | 41.9 | 40.6 | 38.4 |
| space3 | | | |
| Population - 2010 | 4,878 | 12,996 | 309,327,143 |
| Population - 2000 | 5,151 | 14,194 | 285,036,114 |
| Population - 1990 | 3,796 | 13,747 | 251,960,433 |
| Pop. 2000 to Now | 1.9% | -6.8% | 15.6% |
| Pop. 1990 to Now | 38.3% | -3.8% | 30.8% |
| space4 | | | |
| Population Density | 1,441.4 | 5,134.9 | 93.4 |
| Land Area | 3.9 | 2.6 | 3,531,905.4 |
| Water Area | 0.0 | 6.7 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Poolesville, MD | Carpinteria, CA | United States |
| Age 0 to 4 | 6.9% | 5.7% | 5.9% |
| Age 5 to 9 | 8.4% | 7.2% | 6.1% |
| Age 10 to 14 | 6.0% | 6.6% | 6.6% |
| Age 15 to 17 | 3.6% | 2.5% | 3.9% |
| Age 18 to 20 | 3.4% | 3.3% | 4.0% |
| Age 21 to 24 | 6.8% | 4.3% | 5.2% |
| Age 25 to 34 | 5.7% | 11.3% | 13.8% |
| Age 35 to 44 | 14.2% | 13.5% | 12.9% |
| Age 45 to 54 | 19.0% | 10.1% | 12.6% |
| Age 55 to 59 | 8.2% | 6.8% | 6.7% |
| Age 60 to 64 | 4.3% | 7.9% | 6.3% |
| Age 65 to 74 | 7.4% | 14.6% | 9.6% |
| Age 75 to 84 | 3.9% | 4.4% | 4.5% |
| Age 85 and over | 2.1% | 1.9% | 1.9% |
| space1 | | | |
| Race | | | |
| | Poolesville, MD | Carpinteria, CA | United States |
| White | 79.9% | 47.8% | 59.4% |
| Black | 1.1% | 0.7% | 12.2% |
| Asian | 3.6% | 2.1% | 5.6% |
| Native American | 0.0% | 0.0% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.0% | 0.3% | 0.4% |
| Two or More Races | 2.0% | 3.3% | 3.2% |
| Hispanic | 13.3% | 45.7% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Poolesville, MD | Carpinteria, CA | United States |
| Married Population | 63.7% | 56.4% | 49.8% |
| Currently Married | 63.7% | 54.4% | 48.0% |
| Married but Separated | 0.0% | 2.0% | 1.8% |
| Single Population | 36.3% | 43.6% | 50.2% |
| Never Married | 24.3% | 26.0% | 33.8% |
| Divorced | 8.0% | 12.2% | 10.8% |
| Widowed | 3.9% | 5.4% | 5.6% |
| space5 | | | |
| Household Size | 3.12 | 2.67 | 2.60 |
| Households | 1,813 | 4,958 | 124,010,992 |
| Family Households | 1,590 | 3,173 | 80,755,759 |
| Married couple, w/children | 46.8% | 35.7% | 30.5% |
| Married couple, no children | 38.4% | 46.9% | 42.9% |
| Non Family Households | 223 | 1,785 | 43,255,233 |
| Single householder, w/children | 5.5% | 10.4% | 15.8% |
| Single householder, no children | 9.2% | 7.0% | 10.8% |