The calculated distance (air line) between Saarijärvi and Lappeenranta is approximately 149 miles respectively 239 kilometers.
By car or train, the actual journey to Lappeenranta is certainly longer, as only the direct route (as the crow flies) between Saarijärvi and Lappeenranta has been calculated here.
Air line (approximately)
239 kilometers
129 nautical miles