The calculated distance (air line) between Wichian Buri and Udon Thani is approximately 165 miles respectively 265 kilometers.
By car or train, the actual journey to Udon Thani is certainly longer, as only the direct route (as the crow flies) between Wichian Buri and Udon Thani has been calculated here.
Air line (approximately)
265 kilometers
143 nautical miles