The calculated distance (air line) between Khon Kaen and Suwannaphum is approximately 87 miles respectively 140 kilometers.
By car or train, the actual journey to Suwannaphum is certainly longer, as only the direct route (as the crow flies) between Khon Kaen and Suwannaphum has been calculated here.
Air line (approximately)
140 kilometers
75 nautical miles