The calculated distance (air line) between Sint-Pieters-Leeuw and Brugge is approximately 53 miles respectively 86 kilometers.
By car or train, the actual journey to Brugge is certainly longer, as only the direct route (as the crow flies) between Sint-Pieters-Leeuw and Brugge has been calculated here.
Air line (approximately)
86 kilometers
46 nautical miles