The calculated distance (air line) between Bochum-Hordel and Oudenaarde is approximately 161 miles respectively 259 kilometers.
By car or train, the actual journey to Oudenaarde is certainly longer, as only the direct route (as the crow flies) between Bochum-Hordel and Oudenaarde has been calculated here.
Air line (approximately)
259 kilometers
140 nautical miles