The calculated distance (air line) between Hollogne-aux-Pierres and Leuven is approximately 38 miles respectively 60 kilometers.
By car or train, the actual journey to Leuven is certainly longer, as only the direct route (as the crow flies) between Hollogne-aux-Pierres and Leuven has been calculated here.
Air line (approximately)
60 kilometers
33 nautical miles