The calculated distance (air line) between Chon Daen and Nakhon Pathom is approximately 173 miles respectively 278 kilometers.
By car or train, the actual journey to Nakhon Pathom is certainly longer, as only the direct route (as the crow flies) between Chon Daen and Nakhon Pathom has been calculated here.
Air line (approximately)
278 kilometers
150 nautical miles