The calculated distance (air line) between La Chaux-de-Fonds and Luzern is approximately 70 miles respectively 112 kilometers.
By car or train, the actual journey to Luzern is certainly longer, as only the direct route (as the crow flies) between La Chaux-de-Fonds and Luzern has been calculated here.
Air line (approximately)
112 kilometers
61 nautical miles