The calculated distance (air line) between Düsseldorf and Mons-en-Barœul is approximately 164 miles respectively 265 kilometers.
By car or train, the actual journey to Mons-en-Barœul is certainly longer, as only the direct route (as the crow flies) between Düsseldorf and Mons-en-Barœul has been calculated here.
Air line (approximately)
265 kilometers
143 nautical miles