Kvadraturen is a borough in the city centre of the city of Kristiansand which lies in the municipality of Kristiansand in Agder county, Norway. It has a population of 6,750 (2015). The borough is made up of the centre together with the harbour to the south and the more rural district of "Eg" to the north. Kvadraturen is the administrative centre of the municipality of Kristiansand as well as the administrative centre of Vest-Agder county, but is far smaller in area than the other boroughs in the municipality, such as the borough of Grim to the north and west, and the borough of Lund to the east.