The calculated distance (air line) between Schönau am Königssee and Nürnberg is approximately 155 miles respectively 250 kilometers.
By car or train, the actual journey to Nürnberg is certainly longer, as only the direct route (as the crow flies) between Schönau am Königssee and Nürnberg has been calculated here.
Air line (approximately)
250 kilometers
135 nautical miles