The calculated distance (air line) between Donji Vakuf and Banja Luka is approximately 45 miles respectively 72 kilometers.
By car or train, the actual journey to Banja Luka is certainly longer, as only the direct route (as the crow flies) between Donji Vakuf and Banja Luka has been calculated here.
Air line (approximately)
72 kilometers
39 nautical miles