The calculated distance (air line) between Phak Hai and Bang Khun Thian is approximately 55 miles respectively 89 kilometers.
By car or train, the actual journey to Bang Khun Thian is certainly longer, as only the direct route (as the crow flies) between Phak Hai and Bang Khun Thian has been calculated here.
Air line (approximately)
89 kilometers
48 nautical miles