The calculated distance (air line) between Knysna and Graaff-Reinet is approximately 150 miles respectively 242 kilometers.
By car or train, the actual journey to Graaff-Reinet is certainly longer, as only the direct route (as the crow flies) between Knysna and Graaff-Reinet has been calculated here.
Air line (approximately)
242 kilometers
130 nautical miles