The calculated distance (air line) between Nong Wua So and Udon Thani is approximately 22 miles respectively 36 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 Wua So and Udon Thani has been calculated here.
Air line (approximately)
36 kilometers
19 nautical miles