The calculated distance (air line) between Niedobczyce and Ruda Śląska is approximately 21 miles respectively 33 kilometers.
By car or train, the actual journey to Ruda Śląska is certainly longer, as only the direct route (as the crow flies) between Niedobczyce and Ruda Śląska has been calculated here.
Air line (approximately)
33 kilometers
18 nautical miles