The calculated distance (air line) between Pieksämäki and Nurmijärvi is approximately 148 miles respectively 239 kilometers.
By car or train, the actual journey to Nurmijärvi is certainly longer, as only the direct route (as the crow flies) between Pieksämäki and Nurmijärvi has been calculated here.
Air line (approximately)
239 kilometers
129 nautical miles