The calculated distance (air line) between Wādī as Sīr and Sūf is approximately 25 miles respectively 40 kilometers.
By car or train, the actual journey to Sūf is certainly longer, as only the direct route (as the crow flies) between Wādī as Sīr and Sūf has been calculated here.
Air line (approximately)
40 kilometers
22 nautical miles