The calculated distance (air line) between Sankt Veit an der Glan and Donaustadt is approximately 141 miles respectively 227 kilometers.
By car or train, the actual journey to Donaustadt is certainly longer, as only the direct route (as the crow flies) between Sankt Veit an der Glan and Donaustadt has been calculated here.
Air line (approximately)
227 kilometers
122 nautical miles