The calculated distance (air line) between Mülheim-Kärlich and Bielefeld is approximately 122 miles respectively 197 kilometers.
By car or train, the actual journey to Bielefeld is certainly longer, as only the direct route (as the crow flies) between Mülheim-Kärlich and Bielefeld has been calculated here.
Air line (approximately)
197 kilometers
106 nautical miles