The calculated distance (air line) between Sint-Katelijne-Waver and Uccle is approximately 20 miles respectively 32 kilometers.
By car or train, the actual journey to Uccle is certainly longer, as only the direct route (as the crow flies) between Sint-Katelijne-Waver and Uccle has been calculated here.
Air line (approximately)
32 kilometers
18 nautical miles