| | Gambrills, MD | Galesville, MD | United States |
| Population | 3,185 | 1,267 | 329,725,481 |
| Female Population | 49.5% | 50.0% | 50.5% |
| Male Population | 50.5% | 50.0% | 49.5% |
| Median Age | 42.5 | 51.1 | 38.4 |
| space3 | | | |
| Population - 2010 | 2,575 | 498 | 309,327,143 |
| Population - 2000 | 1,848 | 519 | 285,036,114 |
| Population - 1990 | 1,956 | 557 | 251,960,433 |
| Pop. 2000 to Now | 55.1% | 18.9% | 15.6% |
| Pop. 1990 to Now | 46.6% | 10.8% | 30.8% |
| space4 | | | |
| Population Density | 421.6 | 976.1 | 93.4 |
| Land Area | 7.6 | 1.3 | 3,531,905.4 |
| Water Area | 0.0 | 0.4 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Gambrills, MD | Galesville, MD | United States |
| Age 0 to 4 | 4.1% | 1.6% | 5.9% |
| Age 5 to 9 | 6.2% | 3.6% | 6.1% |
| Age 10 to 14 | 6.8% | 4.5% | 6.6% |
| Age 15 to 17 | 5.6% | 3.6% | 3.9% |
| Age 18 to 20 | 2.6% | 12.5% | 4.0% |
| Age 21 to 24 | 2.8% | 0.6% | 5.2% |
| Age 25 to 34 | 12.9% | 5.3% | 13.8% |
| Age 35 to 44 | 11.5% | 10.7% | 12.9% |
| Age 45 to 54 | 15.7% | 25.3% | 12.6% |
| Age 55 to 59 | 8.8% | 4.8% | 6.7% |
| Age 60 to 64 | 7.7% | 7.3% | 6.3% |
| Age 65 to 74 | 7.2% | 12.5% | 9.6% |
| Age 75 to 84 | 4.9% | 7.2% | 4.5% |
| Age 85 and over | 3.3% | 0.8% | 1.9% |
| space1 | | | |
| Race | | | |
| | Gambrills, MD | Galesville, MD | United States |
| White | 80.4% | 85.6% | 59.4% |
| Black | 4.1% | 12.6% | 12.2% |
| Asian | 1.9% | 0.0% | 5.6% |
| Native American | 0.0% | 0.0% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.0% | 0.0% | 0.4% |
| Two or More Races | 6.1% | 1.8% | 3.2% |
| Hispanic | 7.4% | 0.0% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Gambrills, MD | Galesville, MD | United States |
| Married Population | 66.5% | 45.3% | 49.8% |
| Currently Married | 65.5% | 44.7% | 48.0% |
| Married but Separated | 1.0% | 0.6% | 1.8% |
| Single Population | 33.5% | 54.7% | 50.2% |
| Never Married | 24.0% | 21.0% | 33.8% |
| Divorced | 5.8% | 27.2% | 10.8% |
| Widowed | 3.7% | 6.5% | 5.6% |
| space5 | | | |
| Household Size | 3.06 | 3.11 | 2.60 |
| Households | 1,042 | 408 | 124,010,992 |
| Family Households | 876 | 328 | 80,755,759 |
| Married couple, w/children | 40.1% | 8.5% | 30.5% |
| Married couple, no children | 49.3% | 52.1% | 42.9% |
| Non Family Households | 166 | 80 | 43,255,233 |
| Single householder, w/children | 2.1% | 30.2% | 15.8% |
| Single householder, no children | 8.6% | 9.1% | 10.8% |