The calculated distance (air line) between Samut Prakan and Kanchanaburi is approximately 76 miles respectively 122 kilometers.
By car or train, the actual journey to Kanchanaburi is certainly longer, as only the direct route (as the crow flies) between Samut Prakan and Kanchanaburi has been calculated here.
Air line (approximately)
122 kilometers
66 nautical miles