Calw is located in the valley of the Nagold in the Northern Black Forest at an altitude between 330 and 630 metres (1,080–2,070 ft) above sea level.

The following streams also exist within the town: the Tälesbach, Ziegelbach, Wurstbrunnenbach, Schießbach, Schlittenbach und Schweinbach.

In the Middle Ages, Calw was an important commercial town, especially in the cloth and leather trades.

In 1945, a small subcamp of Natzweiler-Struthof concentration camp, where parts for aircraft were assembled by female Jewish forced laborers, was located here.

[7] After the World War II, Calw fell into the French zone of occupation and thus came to the newly founded state of Württemberg-Hohenzollern in 1947.

[citation needed] The most prominent resident of Calw was the author and Nobel prize winner Hermann Hesse.

On 1 January 1975, Calw was combined with the communities of Altburg, Hirsau and Stammheim into the town of Calw-Hirsau.

Populations within the town limits of Calw as defined for each date; the numbers are estimates or census results of the respective statistical agencies (by primary residence): Data sources: census results (¹) or data from statistical offices Since the municipal elections of 7 June 2009 the municipal council of Calw has had a total of thirty members (previously there were only twenty-seven).

The municipal election of 25 May 2014 yielded these results:[8] By the 15th century, Calw had an electoral system that chose a new mayor (Bürgermeister) every two years.

The lion on the three-ridged hill is the coat of arms of the counts of Calw, the former lords of the town.

It was formerly a connecting station for the Black Forest Railway to Stuttgart, whose western extension to Calw was closed in 1988.

The Kommando Spezialkräfte (Special Operations Forces) of the German Army has been stationed since 1996 in the Graf Zeppelin barracks (Graf-Zeppelin-Kaserne) near Heumaden in Calw.

Calw has begun catering to the tourist trade, with numerous shops, restaurants, bistros and ice-cream parlours.

Buildings with exposed concrete (bus station, parking garage) have marked the part of the town centre facing the Nagold for years.

A cultural strength of the Hesse Town is music; worth mentioning are the Aurelius-Sängerknaben (Aurelius Boys' Choir), whose fame extends far beyond the borders of Baden-Württemberg.