POPULATION OF CONNECTICUT BY COUNTIES
| County | 2010 | 2017 est. |
| Fairfield | 916,829 | 949,921 |
| Hartford | 894,014 | 895,388 |
| Litchfield | 189,927 | 182,177 |
| Middlesex | 165,676 | 163,410 |
| New Haven | 862,477 | 860,435 |
| New London | 274,055 | 269,033 |
| Tolland | 152,691 | 151,461 |
| Windham | 118,428 | 116,359 |
| Total for the State | 3,574,097 | 3,588,184 |
SQUARE MILES OF CONNECTICUT BY COUNTIES
| County | Square Miles |
| Fairfield |
837.0
|
| Hartford |
750.6
|
| Litchfield |
944.6
|
| Middlesex |
439.1
|
| New Haven |
862.1
|
| New London |
771.7
|
| Tolland |
417.0
|
| Windham |
521.5
|
| Total for the State |
5,543.6
|