The calculated distance (air line) between Poperinge and Woluwe-Saint-Lambert is approximately 74 miles respectively 120 kilometers.
By car or train, the actual journey to Woluwe-Saint-Lambert is certainly longer, as only the direct route (as the crow flies) between Poperinge and Woluwe-Saint-Lambert has been calculated here.
Air line (approximately)
120 kilometers
65 nautical miles