The calculated distance (air line) between Old City and Bayt Ḩānūn is approximately 44 miles respectively 71 kilometers.
By car or train, the actual journey to Bayt Ḩānūn is certainly longer, as only the direct route (as the crow flies) between Old City and Bayt Ḩānūn has been calculated here.
Air line (approximately)
71 kilometers
39 nautical miles