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