The calculated distance (air line) between Saint-Bonnet-de-Mure and Grenoble is approximately 49 miles respectively 78 kilometers.
By car or train, the actual journey to Grenoble is certainly longer, as only the direct route (as the crow flies) between Saint-Bonnet-de-Mure and Grenoble has been calculated here.
Air line (approximately)
78 kilometers
42 nautical miles