The calculated distance (air line) between Zürich (Kreis 11) / Seebach and Rapperswil is approximately 19 miles respectively 30 kilometers.
By car or train, the actual journey to Rapperswil is certainly longer, as only the direct route (as the crow flies) between Zürich (Kreis 11) / Seebach and Rapperswil has been calculated here.
Air line (approximately)
30 kilometers
16 nautical miles