The calculated distance (air line) between Bayt Ḩānūn and Idhnā is approximately 26 miles respectively 42 kilometers.
By car or train, the actual journey to Idhnā is certainly longer, as only the direct route (as the crow flies) between Bayt Ḩānūn and Idhnā has been calculated here.
Air line (approximately)
42 kilometers
22 nautical miles