The calculated distance (air line) between Ratchaburi and Phra Nakhon Si Ayutthaya is approximately 76 miles respectively 122 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 Ratchaburi and Phra Nakhon Si Ayutthaya has been calculated here.
Air line (approximately)
122 kilometers
66 nautical miles