The calculated distance (air line) between Mevasseret Tsiyyon and Modiin Ilit is approximately 11 miles respectively 18 kilometers.
By car or train, the actual journey to Modiin Ilit is certainly longer, as only the direct route (as the crow flies) between Mevasseret Tsiyyon and Modiin Ilit has been calculated here.
Air line (approximately)
18 kilometers
10 nautical miles