The calculated distance (air line) between Jassans-Riottier and Montpellier is approximately 169 miles respectively 273 kilometers.
By car or train, the actual journey to Montpellier is certainly longer, as only the direct route (as the crow flies) between Jassans-Riottier and Montpellier has been calculated here.
Air line (approximately)
273 kilometers
147 nautical miles