| | Monrovia, MD | Bartonsville, MD | United States |
| Population | 2,306 | 2,176 | 329,725,481 |
| Female Population | 44.8% | 52.2% | 50.5% |
| Male Population | 55.2% | 47.8% | 49.5% |
| Median Age | 39.1 | 36 | 38.4 |
| space3 | | | |
| Population - 2010 | 460 | 1,298 | 309,327,143 |
| Population - 2000 | 511 | 1,139 | 285,036,114 |
| Population - 1990 | 431 | 825 | 251,960,433 |
| Pop. 2000 to Now | -30.1% | 54.9% | 15.6% |
| Pop. 1990 to Now | -17.2% | 113.8% | 30.8% |
| space4 | | | |
| Population Density | 1,025.3 | 833.1 | 93.4 |
| Land Area | 2.2 | 2.6 | 3,531,905.4 |
| Water Area | 0.0 | 0.0 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Monrovia, MD | Bartonsville, MD | United States |
| Age 0 to 4 | 4.0% | 8.9% | 5.9% |
| Age 5 to 9 | 6.4% | 8.7% | 6.1% |
| Age 10 to 14 | 6.4% | 6.5% | 6.6% |
| Age 15 to 17 | 4.5% | 6.9% | 3.9% |
| Age 18 to 20 | 2.9% | 4.9% | 4.0% |
| Age 21 to 24 | 8.4% | 3.2% | 5.2% |
| Age 25 to 34 | 5.9% | 8.9% | 13.8% |
| Age 35 to 44 | 23.4% | 18.3% | 12.9% |
| Age 45 to 54 | 15.2% | 14.0% | 12.6% |
| Age 55 to 59 | 7.2% | 5.2% | 6.7% |
| Age 60 to 64 | 4.3% | 5.1% | 6.3% |
| Age 65 to 74 | 8.3% | 6.7% | 9.6% |
| Age 75 to 84 | 1.2% | 2.6% | 4.5% |
| Age 85 and over | 1.9% | 0.0% | 1.9% |
| space1 | | | |
| Race | | | |
| | Monrovia, MD | Bartonsville, MD | United States |
| White | 45.3% | 79.9% | 59.4% |
| Black | 23.1% | 8.9% | 12.2% |
| Asian | 19.6% | 4.8% | 5.6% |
| Native American | 0.0% | 0.1% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 1.0% | 0.2% |
| Other | 0.0% | 0.0% | 0.4% |
| Two or More Races | 8.1% | 2.2% | 3.2% |
| Hispanic | 4.0% | 3.1% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Monrovia, MD | Bartonsville, MD | United States |
| Married Population | 72.5% | 64.8% | 49.8% |
| Currently Married | 72.5% | 63.6% | 48.0% |
| Married but Separated | 0.0% | 1.2% | 1.8% |
| Single Population | 27.5% | 35.2% | 50.2% |
| Never Married | 26.5% | 26.3% | 33.8% |
| Divorced | 0.9% | 7.7% | 10.8% |
| Widowed | 0.0% | 1.2% | 5.6% |
| space5 | | | |
| Household Size | 3.53 | 3.20 | 2.60 |
| Households | 654 | 679 | 124,010,992 |
| Family Households | 597 | 607 | 80,755,759 |
| Married couple, w/children | 49.9% | 42.0% | 30.5% |
| Married couple, no children | 49.2% | 41.5% | 42.9% |
| Non Family Households | 57 | 72 | 43,255,233 |
| Single householder, w/children | 0.8% | 14.7% | 15.8% |
| Single householder, no children | 0.0% | 1.8% | 10.8% |