The calculated distance (air line) between Rapperswil and Zürich (Kreis 4) / Aussersihl is approximately 18 miles respectively 28 kilometers.
By car or train, the actual journey to Zürich (Kreis 4) / Aussersihl is certainly longer, as only the direct route (as the crow flies) between Rapperswil and Zürich (Kreis 4) / Aussersihl has been calculated here.
Air line (approximately)
28 kilometers
15 nautical miles