The calculated distance (air line) between Klagenfurt am Wörthersee and Wiener Neustadt is approximately 122 miles respectively 196 kilometers.
By car or train, the actual journey to Wiener Neustadt is certainly longer, as only the direct route (as the crow flies) between Klagenfurt am Wörthersee and Wiener Neustadt has been calculated here.
Air line (approximately)
196 kilometers
106 nautical miles