[3] The municipality (Gemeinde) of Althengstett is located in the district of Calw, in Baden-Württemberg, one of the 16 States of the Federal Republic of Germany.

Althengstett lies in a transitional landscape between the Northern Black Forest to the west and the Upper Gäu [de] to the east.

[3] A portion of the Federally protected Würm-Heckengäu [de] nature reserve is located in Althengstett's municipal area.

[3] Althengstett's coat of arms displays a white stallion standing and facing left upon green ground upon a field of blue.

The design of the coat of arms is a reference to the name Althengstett, created in on the advice of the Central State Archive Stuttgart [de].