The calculated distance (air line) between Ḩalḩūl and Dayr al Balaḩ is approximately 46 miles respectively 74 kilometers.
By car or train, the actual journey to Dayr al Balaḩ is certainly longer, as only the direct route (as the crow flies) between Ḩalḩūl and Dayr al Balaḩ has been calculated here.
Air line (approximately)
74 kilometers
40 nautical miles