The calculated distance (air line) between Cologne and Mons-en-Barœul is approximately 169 miles respectively 272 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 Cologne and Mons-en-Barœul has been calculated here.
Air line (approximately)
272 kilometers
147 nautical miles