The calculated distance (air line) between Kralupy nad Vltavou and Děčín is approximately 38 miles respectively 61 kilometers.
By car or train, the actual journey to Děčín is certainly longer, as only the direct route (as the crow flies) between Kralupy nad Vltavou and Děčín has been calculated here.
Air line (approximately)
61 kilometers
33 nautical miles