A footbed for sport footwear made of a shell, which defines the general shape of the footwear. The footbed has a sole portion and a padding wall for partially separating the sides and back of a wearer's foot from the shell. The padding wall partially cups the wearer's heel and extending from the back of the wearer's foot along each side of the heel, along each side of the midfoot and along each side of the forefoot. The footbed is adapted for determining the size of the footwear in terms of width. The footbed may further comprise a toe wall portion for determining the size of the footwear in terms of length.