The calculated distance (air line) between Rheinfelden and Zürich (Kreis 10) is approximately 35 miles respectively 56 kilometers.
By car or train, the actual journey to Zürich (Kreis 10) is certainly longer, as only the direct route (as the crow flies) between Rheinfelden and Zürich (Kreis 10) has been calculated here.
Air line (approximately)
56 kilometers
30 nautical miles