The calculated distance (air line) between Jassans-Riottier and Nîmes is approximately 150 miles respectively 241 kilometers.
By car or train, the actual journey to Nîmes is certainly longer, as only the direct route (as the crow flies) between Jassans-Riottier and Nîmes has been calculated here.
Air line (approximately)
241 kilometers
130 nautical miles