 According to the United States Census Bureau, the township has a total area of 29.9 square miles (77.3 km²), all of it land.Sylvania Township is bordered by Homer Township to the north, Summit Township to the east, Wharton Township to the east and south, Portage Township to the west and the borough of Austin to the west.As of the census of 2000, there were 61 people, 29 households, and 20 families residing in the township.