Before the 2019 merger, Wädenswil had an area of 17.4 km² (6.7 sq mi).
 Of this area, 59.3% is used for agricultural purposes, 9.6% is forested, 29.8% is settled (buildings or roads), and the remainder (1.3%) is non-productive (rivers, glaciers or mountains).
 In 1996 housing and buildings made up 20.8% of the total area, while transportation infrastructure made up the rest (9%).
 Of the total unproductive area, water (streams and lakes) made up 0.4% of the area.
 As of 2007 24.5% of the total municipal area was undergoing some type of construction.
Before the 2019 merger, Wädenswil had an area of 17.4 km² (6.7 sq mi).  Of this area, 59.3% is used for agricultural purposes, 9.6% is forested, 29.8% is settled (buildings or roads), and the remainder (1.3%) is non-productive (rivers, glaciers or mountains).  In 1996 housing and buildings made up 20.8% of the total area, while transportation infrastructure made up the rest (9%).  Of the total unproductive area, water (streams and lakes) made up 0.4% of the area.  As of 2007 24.5% of the total municipal area was undergoing some type of construction.
Wädenswil