Calvas is a canton of the Province of Loja, Ecuador, located in the south of the province, bordering Paltas and Gonzanamá in the north, Quilanga and Espíndola in the east, Peru in the south, and Sozoranga in the west. It covers 1700 km² at an altitude of about 1932m. Total population is about 31,000, and the capital city of the canton is Cariamanga.