The calculated distance (air line) between Deutsch-Wagram and Klagenfurt am Wörthersee is approximately 157 miles respectively 252 kilometers.
By car or train, the actual journey to Klagenfurt am Wörthersee is certainly longer, as only the direct route (as the crow flies) between Deutsch-Wagram and Klagenfurt am Wörthersee has been calculated here.
Air line (approximately)
252 kilometers
136 nautical miles