|Max. length||22 kilometres (14 mi)|
|Max. width||5 kilometres (3.1 mi)|
|Surface area||46.04 km2 (17.78 sq mi)|
|Average depth||52 metres (171 ft)|
|Shore length1||102.98 kilometres (63.99 mi)|
|Surface elevation||690 metres (2,260 ft)|
|1 Shore length is not a well-defined measure.|
There are several inflows to the 46-square-kilometre (18 sq mi) lake including the lakes Rien, Riasten, and Bolagen. The outflow is regulated by a hydropower dam which water passes through into the river Glomma.
Aursunden is often cited as the source of Glomma river, the longest and largest river in Norway. The actual headwaters are near Aursunden near the start of the Glommadal valley. The locals claim that the headwater of the Glomma river is Mustjønna, a tiny lake about 30 kilometres (19 mi) north of Aursunden.