| | Bellefonte, DE | Delmar, DE | United States |
| Population | 1,294 | 2,241 | 329,725,481 |
| Female Population | 50.5% | 57.7% | 50.5% |
| Male Population | 49.5% | 42.4% | 49.5% |
| Median Age | 41.7 | 39.6 | 38.4 |
| space3 | | | |
| Population - 2010 | 1,191 | 1,588 | 309,327,143 |
| Population - 2000 | 1,249 | 1,407 | 285,036,114 |
| Population - 1990 | 1,243 | 962 | 251,960,433 |
| Pop. 2000 to Now | -6.7% | 33.6% | 15.6% |
| Pop. 1990 to Now | -6.2% | 95.3% | 30.8% |
| space4 | | | |
| Population Density | 7,310.7 | 1,253.4 | 93.4 |
| Land Area | 0.2 | 1.8 | 3,531,905.4 |
| Water Area | 0.0 | 0.0 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Bellefonte, DE | Delmar, DE | United States |
| Age 0 to 4 | 7.1% | 7.3% | 5.9% |
| Age 5 to 9 | 4.2% | 7.2% | 6.1% |
| Age 10 to 14 | 6.0% | 7.9% | 6.6% |
| Age 15 to 17 | 1.7% | 2.2% | 3.9% |
| Age 18 to 20 | 3.0% | 5.0% | 4.0% |
| Age 21 to 24 | 4.1% | 3.3% | 5.2% |
| Age 25 to 34 | 15.5% | 11.7% | 13.8% |
| Age 35 to 44 | 14.1% | 13.3% | 12.9% |
| Age 45 to 54 | 13.4% | 11.9% | 12.6% |
| Age 55 to 59 | 10.5% | 5.4% | 6.7% |
| Age 60 to 64 | 8.7% | 4.7% | 6.3% |
| Age 65 to 74 | 7.9% | 11.3% | 9.6% |
| Age 75 to 84 | 3.0% | 7.0% | 4.5% |
| Age 85 and over | 0.8% | 1.7% | 1.9% |
| space1 | | | |
| Race | | | |
| | Bellefonte, DE | Delmar, DE | United States |
| White | 74.3% | 65.5% | 59.4% |
| Black | 14.8% | 22.9% | 12.2% |
| Asian | 0.4% | 1.7% | 5.6% |
| Native American | 0.0% | 0.0% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 3.3% | 0.0% | 0.4% |
| Two or More Races | 5.3% | 4.8% | 3.2% |
| Hispanic | 1.9% | 5.1% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Bellefonte, DE | Delmar, DE | United States |
| Married Population | 41.4% | 38.4% | 49.8% |
| Currently Married | 40.5% | 38.0% | 48.0% |
| Married but Separated | 0.9% | 0.5% | 1.8% |
| Single Population | 58.6% | 61.6% | 50.2% |
| Never Married | 39.3% | 31.9% | 33.8% |
| Divorced | 13.9% | 19.6% | 10.8% |
| Widowed | 5.4% | 10.1% | 5.6% |
| space5 | | | |
| Household Size | 2.47 | 2.54 | 2.60 |
| Households | 523 | 846 | 124,010,992 |
| Family Households | 289 | 489 | 80,755,759 |
| Married couple, w/children | 21.5% | 26.8% | 30.5% |
| Married couple, no children | 47.8% | 32.9% | 42.9% |
| Non Family Households | 234 | 357 | 43,255,233 |
| Single householder, w/children | 23.5% | 27.0% | 15.8% |
| Single householder, no children | 7.3% | 13.3% | 10.8% |