The calculated distance (air line) between Pathum Thani and Krathum Baen is approximately 31 miles respectively 50 kilometers.
By car or train, the actual journey to Krathum Baen is certainly longer, as only the direct route (as the crow flies) between Pathum Thani and Krathum Baen has been calculated here.
Air line (approximately)
50 kilometers
27 nautical miles