The calculated distance (air line) between Myeik and Prachuap Khiri Khan is approximately 91 miles respectively 146 kilometers.
By car or train, the actual journey to Prachuap Khiri Khan is certainly longer, as only the direct route (as the crow flies) between Myeik and Prachuap Khiri Khan has been calculated here.
Air line (approximately)
146 kilometers
79 nautical miles