The calculated distance (air line) between Čáslav and Jablonec nad Nisou is approximately 57 miles respectively 92 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 Čáslav and Jablonec nad Nisou has been calculated here.
Air line (approximately)
92 kilometers
50 nautical miles