The calculated distance (air line) between Jūybār and Gonbad-e Kāvūs is approximately 131 miles respectively 212 kilometers.
By car or train, the actual journey to Gonbad-e Kāvūs is certainly longer, as only the direct route (as the crow flies) between Jūybār and Gonbad-e Kāvūs has been calculated here.
Air line (approximately)
212 kilometers
114 nautical miles