The calculated distance (air line) between Umm as Sāhik and Khobar is approximately 32 miles respectively 51 kilometers.
By car or train, the actual journey to Khobar is certainly longer, as only the direct route (as the crow flies) between Umm as Sāhik and Khobar has been calculated here.
Air line (approximately)
51 kilometers
27 nautical miles