The calculated distance (air line) between Khon Kaen and Nong Kung Si is approximately 34 miles respectively 55 kilometers.
By car or train, the actual journey to Nong Kung Si is certainly longer, as only the direct route (as the crow flies) between Khon Kaen and Nong Kung Si has been calculated here.
Air line (approximately)
55 kilometers
30 nautical miles