The calculated distance (air line) between Thap Khlo and Krathum Baen is approximately 175 miles respectively 281 kilometers.
By car or train, the actual journey to Krathum Baen is certainly longer, as only the direct route (as the crow flies) between Thap Khlo and Krathum Baen has been calculated here.
Air line (approximately)
281 kilometers
152 nautical miles