| | Berlin, CT | Niantic, CT | United States |
| Population | 20,107 | 3,240 | 329,725,481 |
| Female Population | 51.6% | 54.3% | 50.5% |
| Male Population | 48.4% | 45.7% | 49.5% |
| Median Age | 47.6 | 56.1 | 38.4 |
| space3 | | | |
| Population - 2010 | 19,900 | 2,933 | 309,327,143 |
| Population - 2000 | 18,215 | 3,085 | 285,036,114 |
| Population - 1990 | 16,787 | 3,048 | 251,960,433 |
| Pop. 2000 to Now | 11.9% | -7.1% | 15.6% |
| Pop. 1990 to Now | 21.5% | -6.0% | 30.8% |
| space4 | | | |
| Population Density | 763.5 | 2,186.2 | 93.4 |
| Land Area | 26.3 | 1.5 | 3,531,905.4 |
| Water Area | 0.6 | 2.1 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Berlin, CT | Niantic, CT | United States |
| Age 0 to 4 | 4.5% | 3.6% | 5.9% |
| Age 5 to 9 | 6.6% | 5.0% | 6.1% |
| Age 10 to 14 | 5.4% | 2.4% | 6.6% |
| Age 15 to 17 | 4.4% | 3.1% | 3.9% |
| Age 18 to 20 | 3.4% | 1.1% | 4.0% |
| Age 21 to 24 | 3.6% | 1.0% | 5.2% |
| Age 25 to 34 | 8.8% | 11.0% | 13.8% |
| Age 35 to 44 | 10.4% | 10.8% | 12.9% |
| Age 45 to 54 | 14.1% | 10.3% | 12.6% |
| Age 55 to 59 | 10.8% | 7.7% | 6.7% |
| Age 60 to 64 | 6.7% | 11.9% | 6.3% |
| Age 65 to 74 | 11.0% | 19.2% | 9.6% |
| Age 75 to 84 | 6.7% | 9.6% | 4.5% |
| Age 85 and over | 3.7% | 3.2% | 1.9% |
| space1 | | | |
| Race | | | |
| | Berlin, CT | Niantic, CT | United States |
| White | 87.2% | 91.6% | 59.4% |
| Black | 0.4% | 0.7% | 12.2% |
| Asian | 5.4% | 1.0% | 5.6% |
| Native American | 0.0% | 0.0% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.4% | 0.0% | 0.4% |
| Two or More Races | 1.7% | 6.4% | 3.2% |
| Hispanic | 4.9% | 0.2% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Berlin, CT | Niantic, CT | United States |
| Married Population | 57.8% | 58.1% | 49.8% |
| Currently Married | 57.7% | 58.1% | 48.0% |
| Married but Separated | 0.2% | 0.0% | 1.8% |
| Single Population | 42.2% | 41.9% | 50.2% |
| Never Married | 25.1% | 18.0% | 33.8% |
| Divorced | 9.8% | 15.4% | 10.8% |
| Widowed | 7.3% | 8.5% | 5.6% |
| space5 | | | |
| Household Size | 2.47 | 2.10 | 2.60 |
| Households | 8,105 | 1,521 | 124,010,992 |
| Family Households | 6,012 | 908 | 80,755,759 |
| Married couple, w/children | 29.5% | 30.5% | 30.5% |
| Married couple, no children | 49.2% | 57.2% | 42.9% |
| Non Family Households | 2,093 | 613 | 43,255,233 |
| Single householder, w/children | 11.6% | 4.3% | 15.8% |
| Single householder, no children | 9.6% | 8.0% | 10.8% |