The calculated distance (air line) between Saint-Mandrier-sur-Mer and Grenoble is approximately 146 miles respectively 234 kilometers.
By car or train, the actual journey to Grenoble is certainly longer, as only the direct route (as the crow flies) between Saint-Mandrier-sur-Mer and Grenoble has been calculated here.
Air line (approximately)
234 kilometers
126 nautical miles