The calculated distance (air line) between Bethlehem and Bayt Lāhyā is approximately 43 miles respectively 69 kilometers.
By car or train, the actual journey to Bayt Lāhyā is certainly longer, as only the direct route (as the crow flies) between Bethlehem and Bayt Lāhyā has been calculated here.
Air line (approximately)
69 kilometers
37 nautical miles