The calculated distance (air line) between Sedlčany and Jablonec nad Nisou is approximately 81 miles respectively 130 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 Sedlčany and Jablonec nad Nisou has been calculated here.
Air line (approximately)
130 kilometers
70 nautical miles