The calculated distance (air line) between Pieksämäki and Jyväskylä is approximately 46 miles respectively 73 kilometers.
By car or train, the actual journey to Jyväskylä is certainly longer, as only the direct route (as the crow flies) between Pieksämäki and Jyväskylä has been calculated here.
Air line (approximately)
73 kilometers
40 nautical miles