The calculated distance (air line) between Bielefeld and Mechelen-aan-de-Maas is approximately 143 miles respectively 230 kilometers.
By car or train, the actual journey to Mechelen-aan-de-Maas is certainly longer, as only the direct route (as the crow flies) between Bielefeld and Mechelen-aan-de-Maas has been calculated here.
Air line (approximately)
230 kilometers
124 nautical miles