The calculated distance (air line) between Zürich (Kreis 7) / Witikon and Riehen is approximately 47 miles respectively 75 kilometers.
By car or train, the actual journey to Riehen is certainly longer, as only the direct route (as the crow flies) between Zürich (Kreis 7) / Witikon and Riehen has been calculated here.
Air line (approximately)
75 kilometers
41 nautical miles