The calculated distance (air line) between Lat Yao and Krathum Baen is approximately 148 miles respectively 239 kilometers.
By car or train, the actual journey to Krathum Baen is certainly longer, as only the direct route (as the crow flies) between Lat Yao and Krathum Baen has been calculated here.
Air line (approximately)
239 kilometers
129 nautical miles