The calculated distance (air line) between Prachuap Khiri Khan and Chon Buri is approximately 134 miles respectively 215 kilometers.
By car or train, the actual journey to Chon Buri is certainly longer, as only the direct route (as the crow flies) between Prachuap Khiri Khan and Chon Buri has been calculated here.
Air line (approximately)
215 kilometers
116 nautical miles