It is the third largest freshwater Loch in Scotland with a surface area of 38.5 square kilometres (14.9 sq mi).
It is the longest freshwater loch in Scotland, measuring 41 kilometres (25 mi) from end to end with an average width of 1-kilometre (0.62 mi). The loch runs approximately south-west to north-east, roughly parallel to the two sea lochs of Loch Etive and Loch Fyne.
