The calculated distance (air line) between Gerasdorf bei Wien and Klagenfurt am Wörthersee is approximately 153 miles respectively 247 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 Gerasdorf bei Wien and Klagenfurt am Wörthersee has been calculated here.
Air line (approximately)
247 kilometers
133 nautical miles