The calculated distance (air line) between Kreuzlingen and La Chaux-de-Fonds is approximately 116 miles respectively 187 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 Kreuzlingen and La Chaux-de-Fonds has been calculated here.
Air line (approximately)
187 kilometers
101 nautical miles