The calculated distance (air line) between Nakhon Nayok and Nakhon Sawan is approximately 126 miles respectively 203 kilometers.
By car or train, the actual journey to Nakhon Sawan is certainly longer, as only the direct route (as the crow flies) between Nakhon Nayok and Nakhon Sawan has been calculated here.
Air line (approximately)
203 kilometers
110 nautical miles