The calculated distance (air line) between Nablus and Bayt Lāhyā is approximately 64 miles respectively 104 kilometers.
By car or train, the actual journey to Bayt Lāhyā is certainly longer, as only the direct route (as the crow flies) between Nablus and Bayt Lāhyā has been calculated here.
Air line (approximately)
104 kilometers
56 nautical miles