The calculated distance (air line) between Castelnau-le-Lez and Nîmes is approximately 27 miles respectively 43 kilometers.
By car or train, the actual journey to Nîmes is certainly longer, as only the direct route (as the crow flies) between Castelnau-le-Lez and Nîmes has been calculated here.
Air line (approximately)
43 kilometers
23 nautical miles