The calculated distance (air line) between Ubon Ratchathani and Amnat Charoen is approximately 45 miles respectively 73 kilometers.
By car or train, the actual journey to Amnat Charoen is certainly longer, as only the direct route (as the crow flies) between Ubon Ratchathani and Amnat Charoen has been calculated here.
Air line (approximately)
73 kilometers
39 nautical miles