The calculated distance (air line) between Braunschweig and Königslutter am Elm is approximately 12 miles respectively 20 kilometers.
By car or train, the actual journey to Königslutter am Elm is certainly longer, as only the direct route (as the crow flies) between Braunschweig and Königslutter am Elm has been calculated here.
Air line (approximately)
20 kilometers
11 nautical miles