The calculated distance (air line) between Roztoky and Jablonec nad Nisou is approximately 52 miles respectively 83 kilometers.
By car or train, the actual journey to Jablonec nad Nisou is certainly longer, as only the direct route (as the crow flies) between Roztoky and Jablonec nad Nisou has been calculated here.
Air line (approximately)
83 kilometers
45 nautical miles