The calculated distance (air line) between Klosterneuburg and Wiener Neustadt is approximately 35 miles respectively 56 kilometers.
By car or train, the actual journey to Wiener Neustadt is certainly longer, as only the direct route (as the crow flies) between Klosterneuburg and Wiener Neustadt has been calculated here.
Air line (approximately)
56 kilometers
30 nautical miles