The calculated distance (air line) between Portes-lès-Valence and Nîmes is approximately 76 miles respectively 123 kilometers.
By car or train, the actual journey to Nîmes is certainly longer, as only the direct route (as the crow flies) between Portes-lès-Valence and Nîmes has been calculated here.
Air line (approximately)
123 kilometers
66 nautical miles