The calculated distance (air line) between Budapest XXIII. kerület and Dunaújváros is approximately 31 miles respectively 50 kilometers.
By car or train, the actual journey to Dunaújváros is certainly longer, as only the direct route (as the crow flies) between Budapest XXIII. kerület and Dunaújváros has been calculated here.
Air line (approximately)
50 kilometers
27 nautical miles