| | Miami Beach, FL | Flagler Beach, FL | United States |
| Population | 83,469 | 5,064 | 329,725,481 |
| Female Population | 49.1% | 52.1% | 50.5% |
| Male Population | 50.9% | 47.9% | 49.5% |
| Median Age | 41.7 | 59.1 | 38.4 |
| space3 | | | |
| Population - 2010 | 87,722 | 4,518 | 309,327,143 |
| Population - 2000 | 87,933 | 4,954 | 285,036,114 |
| Population - 1990 | 92,639 | 3,820 | 251,960,433 |
| Pop. 2000 to Now | -0.2% | 4.0% | 15.6% |
| Pop. 1990 to Now | -5.3% | 34.9% | 30.8% |
| space4 | | | |
| Population Density | 10,851.4 | 1,413.0 | 93.4 |
| Land Area | 7.7 | 3.6 | 3,531,905.4 |
| Water Area | 7.5 | 0.5 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Miami Beach, FL | Flagler Beach, FL | United States |
| Age 0 to 4 | 5.4% | 3.0% | 5.9% |
| Age 5 to 9 | 4.2% | 2.1% | 6.1% |
| Age 10 to 14 | 3.6% | 2.8% | 6.6% |
| Age 15 to 17 | 2.4% | 2.0% | 3.9% |
| Age 18 to 20 | 2.3% | 1.6% | 4.0% |
| Age 21 to 24 | 3.7% | 1.7% | 5.2% |
| Age 25 to 34 | 16.7% | 6.6% | 13.8% |
| Age 35 to 44 | 16.9% | 5.4% | 12.9% |
| Age 45 to 54 | 15.4% | 13.8% | 12.6% |
| Age 55 to 59 | 6.6% | 17.3% | 6.7% |
| Age 60 to 64 | 5.6% | 10.5% | 6.3% |
| Age 65 to 74 | 9.5% | 18.9% | 9.6% |
| Age 75 to 84 | 5.0% | 9.9% | 4.5% |
| Age 85 and over | 2.6% | 4.7% | 1.9% |
| space1 | | | |
| Race | | | |
| | Miami Beach, FL | Flagler Beach, FL | United States |
| White | 35.2% | 89.8% | 59.4% |
| Black | 3.5% | 2.9% | 12.2% |
| Asian | 1.8% | 0.5% | 5.6% |
| Native American | 0.1% | 1.2% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 1.1% | 0.0% | 0.4% |
| Two or More Races | 2.3% | 1.0% | 3.2% |
| Hispanic | 56.1% | 4.6% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Miami Beach, FL | Flagler Beach, FL | United States |
| Married Population | 45.4% | 63.0% | 49.8% |
| Currently Married | 41.2% | 62.2% | 48.0% |
| Married but Separated | 4.2% | 0.8% | 1.8% |
| Single Population | 54.6% | 37.0% | 50.2% |
| Never Married | 35.1% | 17.4% | 33.8% |
| Divorced | 15.6% | 9.2% | 10.8% |
| Widowed | 4.0% | 10.5% | 5.6% |
| space5 | | | |
| Household Size | 1.99 | 2.04 | 2.60 |
| Households | 41,533 | 2,481 | 124,010,992 |
| Family Households | 18,445 | 1,554 | 80,755,759 |
| Married couple, w/children | 25.1% | 13.4% | 30.5% |
| Married couple, no children | 49.3% | 74.2% | 42.9% |
| Non Family Households | 23,088 | 927 | 43,255,233 |
| Single householder, w/children | 13.2% | 7.9% | 15.8% |
| Single householder, no children | 12.4% | 4.6% | 10.8% |