The calculated distance (air line) between Nakhon Phanom and Savannakhet is approximately 58 miles respectively 93 kilometers.
By car or train, the actual journey to Savannakhet is certainly longer, as only the direct route (as the crow flies) between Nakhon Phanom and Savannakhet has been calculated here.
Air line (approximately)
93 kilometers
50 nautical miles