[1] The cabecera or municipal seat is primarily mestizo, while the outlying communities (including Papatlatla, Tula, Atempa, and Ahuacatlan) are heavily populated by Nahuatl-speaking indigenous people.

Despite its small size, Calnali is important as a regional cultural center, hosting an annual music festival featuring local Bandas de Viento and huapango performers, as well as an annual festival of indigenous culture.

Large celebrations are also held for the Day of the Dead, Carnival and 25 April which is the festival of Calnali's patron saint, San Marcos.

In 2009, over the objections of the municipal administration, the Diocese of Huejutla temporarily suspended all Catholic Church functions in Calnali, including baptisms and funerals, in response to indigenous carnival activities on Ash Wednesday.

Central Calnali is located at 980 m elevation, and the entire municipality occupies the eastern slope of the Sierra Madre Oriental.