The calculated distance (air line) between Altdorf bei Nurnberg and Nürnberg is approximately 13 miles respectively 22 kilometers.
By car or train, the actual journey to Nürnberg is certainly longer, as only the direct route (as the crow flies) between Altdorf bei Nurnberg and Nürnberg has been calculated here.
Air line (approximately)
22 kilometers
12 nautical miles