The calculated distance (air line) between Tha Ruea and Krathum Baen is approximately 70 miles respectively 113 kilometers.
By car or train, the actual journey to Krathum Baen is certainly longer, as only the direct route (as the crow flies) between Tha Ruea and Krathum Baen has been calculated here.
Air line (approximately)
113 kilometers
61 nautical miles