The calculated distance (air line) between Zürich (Kreis 11) / Oerlikon and Schaffhausen is approximately 20 miles respectively 33 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 11) / Oerlikon and Schaffhausen has been calculated here.
Air line (approximately)
33 kilometers
18 nautical miles