The calculated distance (air line) between Al Bīrah and Bayt Lāhyā is approximately 49 miles respectively 79 kilometers.
By car or train, the actual journey to Bayt Lāhyā is certainly longer, as only the direct route (as the crow flies) between Al Bīrah and Bayt Lāhyā has been calculated here.
Air line (approximately)
79 kilometers
43 nautical miles