The calculated distance (air line) between Zürich (Kreis 7) / Witikon and Schaffhausen is approximately 24 miles respectively 38 kilometers.
By car or train, the actual journey to Schaffhausen is certainly longer, as only the direct route (as the crow flies) between Zürich (Kreis 7) / Witikon and Schaffhausen has been calculated here.
Air line (approximately)
38 kilometers
20 nautical miles