The calculated distance (air line) between Hainburg an der Donau and Floridsdorf is approximately 26 miles respectively 42 kilometers.
By car or train, the actual journey to Floridsdorf is certainly longer, as only the direct route (as the crow flies) between Hainburg an der Donau and Floridsdorf has been calculated here.
Air line (approximately)
42 kilometers
23 nautical miles