The calculated distance (air line) between Bochum-Hordel and Heerenveen is approximately 114 miles respectively 183 kilometers.
By car or train, the actual journey to Heerenveen is certainly longer, as only the direct route (as the crow flies) between Bochum-Hordel and Heerenveen has been calculated here.
Air line (approximately)
183 kilometers
99 nautical miles