The calculated distance (air line) between Wādī as Sīr and Mādabā is approximately 17 miles respectively 27 kilometers.
By car or train, the actual journey to Mādabā is certainly longer, as only the direct route (as the crow flies) between Wādī as Sīr and Mādabā has been calculated here.
Air line (approximately)
27 kilometers
14 nautical miles