The calculated distance (air line) between Konstancin-Jeziorna and Kielce is approximately 87 miles respectively 140 kilometers.
By car or train, the actual journey to Kielce is certainly longer, as only the direct route (as the crow flies) between Konstancin-Jeziorna and Kielce has been calculated here.
Air line (approximately)
140 kilometers
76 nautical miles