Winnetka is a village located approximately 14 miles (23 km) north of downtown Chicago in Cook County, Illinois. Winnetka is located at 42°6′22″N 87°44′16″W / 42.10611°N 87.73778°W / 42.10611; -87.73778Coordinates: 42°6′22″N 87°44′16″W / 42.10611°N 87.73778°W / 42.10611; -87.73778 (42.106227, -87.73801).. Winnetka is located 198m (650ft) above sea level and has a magnetic declination of 3° 10' W. According to the United States Census Bureau, the village has a total area of 3.9 square miles, of which 3.8 sq mi (9.8 km) is land and 0.1 sq mi (0.26 km) (2.30%) is water.