The calculated distance (air line) between Châlette-sur-Loing and Besançon is approximately 162 miles respectively 260 kilometers.
By car or train, the actual journey to Besançon is certainly longer, as only the direct route (as the crow flies) between Châlette-sur-Loing and Besançon has been calculated here.
Air line (approximately)
260 kilometers
140 nautical miles