Tamins has an area, as of 2006, of 40.7 km² (15.7 sq mi).
 Of this area, 16.5% is used for agricultural purposes, while 50.1% is forested.
 Of the rest of the land, 1.4% is settled (buildings or roads) and the remainder (32%) is non-productive (rivers, glaciers or mountains).

Before 2017, the municipality was located in the Trins sub-district, of the Imboden district, after 2017 it was part of the Imboden Region.
 It is a small settlement north of the confluence of the Hinterrhein and Vorderrhein.
 It consists of the village of Tamins and since 1803 the village of Reichenau at the confluence of Hinterrhein and Vorderrhein and the Castle (Schloss) of Reichenau.

is located in the municipality.
Tamins has an area, as of 2006, of 40.7 km² (15.7 sq mi).  Of this area, 16.5% is used for agricultural purposes, while 50.1% is forested.  Of the rest of the land, 1.4% is settled (buildings or roads) and the remainder (32%) is non-productive (rivers, glaciers or mountains).
Before 2017, the municipality was located in the Trins sub-district, of the Imboden district, after 2017 it was part of the Imboden Region.  It is a small settlement north of the confluence of the Hinterrhein and Vorderrhein.  It consists of the village of Tamins and since 1803 the village of Reichenau at the confluence of Hinterrhein and Vorderrhein and the Castle (Schloss) of Reichenau.
is located in the municipality.
Tamins