The calculated distance (air line) between Lons-le-Saunier and Besançon is approximately 45 miles respectively 73 kilometers.
By car or train, the actual journey to Besançon is certainly longer, as only the direct route (as the crow flies) between Lons-le-Saunier and Besançon has been calculated here.
Air line (approximately)
73 kilometers
39 nautical miles