The calculated distance (air line) between Phanom Thuan and Samut Prakan is approximately 71 miles respectively 114 kilometers.
By car or train, the actual journey to Samut Prakan is certainly longer, as only the direct route (as the crow flies) between Phanom Thuan and Samut Prakan has been calculated here.
Air line (approximately)
114 kilometers
61 nautical miles