The calculated distance (air line) between Duisburg and Sint-Kwintens-Lennik is approximately 121 miles respectively 195 kilometers.
By car or train, the actual journey to Sint-Kwintens-Lennik is certainly longer, as only the direct route (as the crow flies) between Duisburg and Sint-Kwintens-Lennik has been calculated here.
Air line (approximately)
195 kilometers
105 nautical miles