The calculated distance (air line) between Nakhon Ratchasima and Ubon Ratchathani is approximately 184 miles respectively 296 kilometers.
By car or train, the actual journey to Ubon Ratchathani is certainly longer, as only the direct route (as the crow flies) between Nakhon Ratchasima and Ubon Ratchathani has been calculated here.
Air line (approximately)
296 kilometers
160 nautical miles