The calculated distance (air line) between Morlanwelz-Mariemont and Leuven is approximately 35 miles respectively 57 kilometers.
By car or train, the actual journey to Leuven is certainly longer, as only the direct route (as the crow flies) between Morlanwelz-Mariemont and Leuven has been calculated here.
Air line (approximately)
57 kilometers
31 nautical miles