As of the 2010 census, the United States Census Bureau reported that 2010 median center of population of the United States was in Clay Township, 7.1 miles (11.4 km) southwest of Petersburg.[2]
According to the 2010 census, the township has a total area of 23.95 square miles (62.0 km2), of which 23.58 square miles (61.1 km2) (or 98.46%) is land and 0.37 square miles (0.96 km2) (or 1.54%) is water.[4] The White River defines the north border of the township, as well as the north border of Pike County.