Males and females possess horns that they retain throughout their existence. Chamois change livery twice a year during an autumn moult (August-September) and a spring moult (April-May).
Chamois can live 25 years, which is a surprisingly long life for animals of this size.

The chamois of the Alps
As adults, the Alpine Chamois is 75 to 80 cm tall at the withers and 120 to 135 cm long, from the snout to the tail. Its weight varies between 35 and 50 kg in males, 25 to 38 kg in females.
The Izard of the Pyrenees
As adults, the Isard des Pyrénées is 70 to 75 cm tall at the withers and 100 to 110 cm long. Its weight varies from 25 to 40 kg for the males and from 20 to 32 kg for the females. Its summer coat is uniformly coloured, reddish beige or ochre.

Criteria for sex recognition of chamois:
Before one year, this distinction is hardly possible, for lack of reliable criteria. Only observation of the kids who urinate can allow it.
The penile brush, which can be spotted, is an infallible criterion, but it is obvious that in fourth-year goats and more, less in third-year goats, exceptionally earlier.