The calculated distance (air line) between Nang Rong and Krathum Baen is approximately 183 miles respectively 294 kilometers.
By car or train, the actual journey to Krathum Baen is certainly longer, as only the direct route (as the crow flies) between Nang Rong and Krathum Baen has been calculated here.
Air line (approximately)
294 kilometers
159 nautical miles