The calculated distance (air line) between Neu-Guntramsdorf and Donaustadt is approximately 13 miles respectively 22 kilometers.
By car or train, the actual journey to Donaustadt is certainly longer, as only the direct route (as the crow flies) between Neu-Guntramsdorf and Donaustadt has been calculated here.
Air line (approximately)
22 kilometers
12 nautical miles