The calculated distance (air line) between Deutsch-Wagram and Neusiedl am See is approximately 27 miles respectively 44 kilometers.
By car or train, the actual journey to Neusiedl am See is certainly longer, as only the direct route (as the crow flies) between Deutsch-Wagram and Neusiedl am See has been calculated here.
Air line (approximately)
44 kilometers
24 nautical miles