The calculated distance (air line) between Ko Lanta and Nakhon Si Thammarat is approximately 87 miles respectively 139 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 Ko Lanta and Nakhon Si Thammarat has been calculated here.
Air line (approximately)
139 kilometers
75 nautical miles