The calculated distance (air line) between Saint-Gervais-les-Bains and Nîmes is approximately 183 miles respectively 295 kilometers.
By car or train, the actual journey to Nîmes is certainly longer, as only the direct route (as the crow flies) between Saint-Gervais-les-Bains and Nîmes has been calculated here.
Air line (approximately)
295 kilometers
159 nautical miles