The calculated distance (air line) between Gasteiz / Vitoria and Santutxu is approximately 30 miles respectively 49 kilometers.
By car or train, the actual journey to Santutxu is certainly longer, as only the direct route (as the crow flies) between Gasteiz / Vitoria and Santutxu has been calculated here.
Air line (approximately)
49 kilometers
26 nautical miles