The municipality of Riner, of 47.21 km2, extends to the right slopes of the Río Negro (which gives it its name), or the Solsona stream, which forms a good part of the northern limit, up to the plateau ( SW) where the important Miracle sanctuary (861m) stands, at the Cardener and Segre watershed, and up to the sector (SE) centered on the town of Su, at the head of the Matamargó stream. Several tributaries flow into the Negro River, such as the Galtanegra and Avellanosa torrents. El Cardener forms part of the NE limit. It limits to the NW with the term of Olius (sector of the S of Solsona), to the NE and to the E with that of Clariana de Cardener and to the S with those of Pinós and Cardona.
The settlement is very scattered and the main population entities are Freixinet, Su, Santa Susanna and El Miracle. The parishes are those of San Jaime de Riner, Santa Susanna, Su and Freixient. the road from Manresa to Solsona, the one from Cardona to the Hostal del Boix (where it connects with the one from Solsona to Torà) and the one from Santa Susanna to Su are the main communication routes, and the farmhouses in the term use municipal or private roads.