The calculated distance (air line) between Khlong Luang and Nakhon Nayok is approximately 39 miles respectively 63 kilometers.
By car or train, the actual journey to Nakhon Nayok is certainly longer, as only the direct route (as the crow flies) between Khlong Luang and Nakhon Nayok has been calculated here.
Air line (approximately)
63 kilometers
34 nautical miles