The calculated distance (air line) between Kandahār and Lashkar Gāh is approximately 79 miles respectively 127 kilometers.
By car or train, the actual journey to Lashkar Gāh is certainly longer, as only the direct route (as the crow flies) between Kandahār and Lashkar Gāh has been calculated here.
Air line (approximately)
127 kilometers
68 nautical miles