The calculated distance (air line) between Mattenbach (Kreis 7) and Luzern is approximately 37 miles respectively 59 kilometers.
By car or train, the actual journey to Luzern is certainly longer, as only the direct route (as the crow flies) between Mattenbach (Kreis 7) and Luzern has been calculated here.
Air line (approximately)
59 kilometers
32 nautical miles