The calculated distance (air line) between Phanat Nikhom and Chon Buri is approximately 15 miles respectively 24 kilometers.
By car or train, the actual journey to Chon Buri is certainly longer, as only the direct route (as the crow flies) between Phanat Nikhom and Chon Buri has been calculated here.
Air line (approximately)
24 kilometers
13 nautical miles