The calculated distance (air line) between Saint-Genest-Lerpt and Besançon is approximately 148 miles respectively 239 kilometers.
By car or train, the actual journey to Besançon is certainly longer, as only the direct route (as the crow flies) between Saint-Genest-Lerpt and Besançon has been calculated here.
Air line (approximately)
239 kilometers
129 nautical miles