The calculated distance (air line) between Davos and La Chaux-de-Fonds is approximately 143 miles respectively 231 kilometers.
By car or train, the actual journey to La Chaux-de-Fonds is certainly longer, as only the direct route (as the crow flies) between Davos and La Chaux-de-Fonds has been calculated here.
Air line (approximately)
231 kilometers
125 nautical miles