The calculated distance (air line) between Dan Khun Thot and Krathum Baen is approximately 148 miles respectively 237 kilometers.
By car or train, the actual journey to Krathum Baen is certainly longer, as only the direct route (as the crow flies) between Dan Khun Thot and Krathum Baen has been calculated here.
Air line (approximately)
237 kilometers
128 nautical miles