The calculated distance (air line) between Prakhon Chai and Khon Kaen is approximately 129 miles respectively 207 kilometers.
By car or train, the actual journey to Khon Kaen is certainly longer, as only the direct route (as the crow flies) between Prakhon Chai and Khon Kaen has been calculated here.
Air line (approximately)
207 kilometers
112 nautical miles