It is located west of Lake Hallwil and covers parts of the Wyna and Suhre valleys.

The principal town is Unterkulm; the largest municipality is Reinach.

[1] Kulm district has an area, as of 2009[update], of 101.37 square kilometers (39.14 sq mi).

Of the rest of the land, 14.4 km2 (5.6 sq mi) or 14.2% is settled (buildings or roads).

[4] From the 2000 census[update], 8,159 or 22.7% were Roman Catholic, while 19,512 or 54.3% belonged to the Swiss Reformed Church.