The calculated distance (air line) between Ubon Ratchathani and Nang Rong is approximately 143 miles respectively 231 kilometers.
By car or train, the actual journey to Nang Rong is certainly longer, as only the direct route (as the crow flies) between Ubon Ratchathani and Nang Rong has been calculated here.
Air line (approximately)
231 kilometers
125 nautical miles