The Baltic Sea is about 1,600 km long, with an average width of 193 km, and an average of 55 m deep. The maximum depth is 459 m. The surface area is about 349,644 km² and the volume is about 20,000 km³. The periphery amounts to about 8,000 km of coastline.
It is bounded by the Swedish part of the Scandinavian Peninsula, the mainland of Europe, and the Danish islands.
The Baltic Sea is situated over a basin formed by glacial erosion during the last few ice ages.