The calculated distance (air line) between Nakhon Nayok and Samut Prakan is approximately 59 miles respectively 95 kilometers.
By car or train, the actual journey to Samut Prakan is certainly longer, as only the direct route (as the crow flies) between Nakhon Nayok and Samut Prakan has been calculated here.
Air line (approximately)
95 kilometers
51 nautical miles