| | Carefree, AZ | Elkridge, MD | United States |
| Population | 3,642 | 24,115 | 329,725,481 |
| Female Population | 49.9% | 54.3% | 50.5% |
| Male Population | 50.1% | 45.7% | 49.5% |
| Median Age | 66.7 | 34.1 | 38.4 |
| space3 | | | |
| Population - 2010 | 3,369 | 13,512 | 309,327,143 |
| Population - 2000 | 2,927 | 22,042 | 285,036,114 |
| Population - 1990 | 1,666 | 12,953 | 251,960,433 |
| Pop. 2000 to Now | 35.8% | -7.4% | 15.6% |
| Pop. 1990 to Now | 138.5% | 57.6% | 30.8% |
| space4 | | | |
| Population Density | 413.5 | 2,874.9 | 93.4 |
| Land Area | 8.8 | 8.4 | 3,531,905.4 |
| Water Area | 0.0 | 0.0 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Carefree, AZ | Elkridge, MD | United States |
| Age 0 to 4 | 0.0% | 8.1% | 5.9% |
| Age 5 to 9 | 0.0% | 7.0% | 6.1% |
| Age 10 to 14 | 0.0% | 9.1% | 6.6% |
| Age 15 to 17 | 1.9% | 3.8% | 3.9% |
| Age 18 to 20 | 3.3% | 2.6% | 4.0% |
| Age 21 to 24 | 1.3% | 4.3% | 5.2% |
| Age 25 to 34 | 2.6% | 17.0% | 13.8% |
| Age 35 to 44 | 1.7% | 16.2% | 12.9% |
| Age 45 to 54 | 14.6% | 12.5% | 12.6% |
| Age 55 to 59 | 10.5% | 6.6% | 6.7% |
| Age 60 to 64 | 9.3% | 4.7% | 6.3% |
| Age 65 to 74 | 23.0% | 5.8% | 9.6% |
| Age 75 to 84 | 26.2% | 1.8% | 4.5% |
| Age 85 and over | 5.6% | 0.2% | 1.9% |
| space1 | | | |
| Race | | | |
| | Carefree, AZ | Elkridge, MD | United States |
| White | 96.8% | 38.3% | 59.4% |
| Black | 1.1% | 32.1% | 12.2% |
| Asian | 0.7% | 20.4% | 5.6% |
| Native American | 0.1% | 0.4% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.0% | 0.0% | 0.4% |
| Two or More Races | 0.1% | 2.8% | 3.2% |
| Hispanic | 1.3% | 6.1% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Carefree, AZ | Elkridge, MD | United States |
| Married Population | 64.3% | 54.0% | 49.8% |
| Currently Married | 64.3% | 51.1% | 48.0% |
| Married but Separated | 0.0% | 2.8% | 1.8% |
| Single Population | 35.7% | 46.0% | 50.2% |
| Never Married | 11.7% | 33.0% | 33.8% |
| Divorced | 13.4% | 10.4% | 10.8% |
| Widowed | 10.6% | 2.6% | 5.6% |
| space5 | | | |
| Household Size | 1.95 | 2.82 | 2.60 |
| Households | 1,839 | 8,527 | 124,010,992 |
| Family Households | 1,225 | 6,071 | 80,755,759 |
| Married couple, w/children | 3.8% | 35.7% | 30.5% |
| Married couple, no children | 92.0% | 36.3% | 42.9% |
| Non Family Households | 614 | 2,456 | 43,255,233 |
| Single householder, w/children | 2.0% | 17.5% | 15.8% |
| Single householder, no children | 2.2% | 10.5% | 10.8% |