The calculated distance (air line) between Thal and La Chaux-de-Fonds is approximately 131 miles respectively 211 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 Thal and La Chaux-de-Fonds has been calculated here.
Air line (approximately)
211 kilometers
114 nautical miles