The calculated distance (air line) between Nong Bua and Udon Thani is approximately 181 miles respectively 291 kilometers.
By car or train, the actual journey to Udon Thani is certainly longer, as only the direct route (as the crow flies) between Nong Bua and Udon Thani has been calculated here.
Air line (approximately)
291 kilometers
157 nautical miles