| | Casco, ME | Westbrook, ME | United States |
| Population | 3,643 | 20,074 | 329,725,481 |
| Female Population | 49.7% | 53.4% | 50.5% |
| Male Population | 50.3% | 46.7% | 49.5% |
| Median Age | 48.6 | 37.7 | 38.4 |
| space3 | | | |
| Population - 2010 | 3,744 | 17,521 | 309,327,143 |
| Population - 2000 | 3,469 | 16,142 | 285,036,114 |
| Population - 1990 | 3,018 | 16,121 | 251,960,433 |
| Pop. 2000 to Now | 13.6% | 19.4% | 15.6% |
| Pop. 1990 to Now | 30.6% | 19.5% | 30.8% |
| space4 | | | |
| Population Density | 116.5 | 1,167.9 | 93.4 |
| Land Area | 31.3 | 17.2 | 3,531,905.4 |
| Water Area | 6.7 | 0.2 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Casco, ME | Westbrook, ME | United States |
| Age 0 to 4 | 3.8% | 4.9% | 5.9% |
| Age 5 to 9 | 5.1% | 3.5% | 6.1% |
| Age 10 to 14 | 3.4% | 5.3% | 6.6% |
| Age 15 to 17 | 2.1% | 3.2% | 3.9% |
| Age 18 to 20 | 1.7% | 2.8% | 4.0% |
| Age 21 to 24 | 8.5% | 4.3% | 5.2% |
| Age 25 to 34 | 13.3% | 21.3% | 13.8% |
| Age 35 to 44 | 7.7% | 11.5% | 12.9% |
| Age 45 to 54 | 19.0% | 11.8% | 12.6% |
| Age 55 to 59 | 8.2% | 8.1% | 6.7% |
| Age 60 to 64 | 6.3% | 5.0% | 6.3% |
| Age 65 to 74 | 10.0% | 9.9% | 9.6% |
| Age 75 to 84 | 8.2% | 5.4% | 4.5% |
| Age 85 and over | 2.6% | 2.9% | 1.9% |
| space1 | | | |
| Race | | | |
| | Casco, ME | Westbrook, ME | United States |
| White | 89.2% | 87.1% | 59.4% |
| Black | 0.3% | 4.4% | 12.2% |
| Asian | 0.5% | 2.2% | 5.6% |
| Native American | 0.0% | 0.1% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.0% | 1.7% | 0.4% |
| Two or More Races | 9.9% | 3.2% | 3.2% |
| Hispanic | 0.2% | 1.4% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Casco, ME | Westbrook, ME | United States |
| Married Population | 43.7% | 45.5% | 49.8% |
| Currently Married | 42.8% | 44.4% | 48.0% |
| Married but Separated | 1.0% | 1.0% | 1.8% |
| Single Population | 56.3% | 54.6% | 50.2% |
| Never Married | 36.2% | 36.5% | 33.8% |
| Divorced | 11.4% | 12.4% | 10.8% |
| Widowed | 8.7% | 5.7% | 5.6% |
| space5 | | | |
| Household Size | 2.13 | 2.26 | 2.60 |
| Households | 1,700 | 8,838 | 124,010,992 |
| Family Households | 844 | 4,691 | 80,755,759 |
| Married couple, w/children | 23.2% | 27.3% | 30.5% |
| Married couple, no children | 53.7% | 50.2% | 42.9% |
| Non Family Households | 856 | 4,147 | 43,255,233 |
| Single householder, w/children | 8.8% | 11.4% | 15.8% |
| Single householder, no children | 14.3% | 11.0% | 10.8% |