The calculated distance (air line) between Surat Thani and Nakhon Si Thammarat is approximately 65 miles respectively 105 kilometers.
By car or train, the actual journey to Nakhon Si Thammarat is certainly longer, as only the direct route (as the crow flies) between Surat Thani and Nakhon Si Thammarat has been calculated here.
Air line (approximately)
105 kilometers
57 nautical miles