The calculated distance (air line) between Kui Buri and Krathum Baen is approximately 112 miles respectively 180 kilometers.
By car or train, the actual journey to Krathum Baen is certainly longer, as only the direct route (as the crow flies) between Kui Buri and Krathum Baen has been calculated here.
Air line (approximately)
180 kilometers
97 nautical miles