The adult snail is around 7 cm (2.8 in) in diameter and 20 cm (7.9 in) or more in length, making it one of the largest of all extant land snails.[21]
The shell has a conical shape, being about twice as long as it is broad. Either clockwise (dextral) or counter-clockwise (sinistral) directions can be observed in the coiling of the shell, although the dextral cone is the more common. Shell colouration is highly variable, and dependent on diet. Typically, brown is the predominant colour and the shell is banded.