The calculated distance (air line) between Chon Buri and Phra Nakhon Si Ayutthaya is approximately 74 miles respectively 118 kilometers.
By car or train, the actual journey to Phra Nakhon Si Ayutthaya is certainly longer, as only the direct route (as the crow flies) between Chon Buri and Phra Nakhon Si Ayutthaya has been calculated here.
Air line (approximately)
118 kilometers
64 nautical miles