It is the third most populous sub-region in Finland with about 351,000 inhabitants after Helsinki and Tampere.

The sub-regions[1] are used for statistical purposes.

[2] Statistics Finland uses the term Turku sub-region as SK023 Turku.

[3] The Turku sub-region differs from the Turku metropolitan area (Greater Turku), which does not include the municipalities of Masku, Mynämäki, Nousiainen, Paimio and Sauvo.

The metropolitan area has a population of about 316,000.