The calculated distance (air line) between Riehen and Zürich (Kreis 12) is approximately 45 miles respectively 72 kilometers.
By car or train, the actual journey to Zürich (Kreis 12) is certainly longer, as only the direct route (as the crow flies) between Riehen and Zürich (Kreis 12) has been calculated here.
Air line (approximately)
72 kilometers
39 nautical miles