The calculated distance (air line) between Nakhon Sawan and Krathum Baen is approximately 142 miles respectively 228 kilometers.
By car or train, the actual journey to Krathum Baen is certainly longer, as only the direct route (as the crow flies) between Nakhon Sawan and Krathum Baen has been calculated here.
Air line (approximately)
228 kilometers
123 nautical miles