The calculated distance (air line) between Demir Kapija and Kriva Palanka is approximately 55 miles respectively 89 kilometers.
By car or train, the actual journey to Kriva Palanka is certainly longer, as only the direct route (as the crow flies) between Demir Kapija and Kriva Palanka has been calculated here.
Air line (approximately)
89 kilometers
48 nautical miles