The calculated distance (air line) between Dannstadt-Schauernheim and Dortmund is approximately 148 miles respectively 238 kilometers.
By car or train, the actual journey to Dortmund is certainly longer, as only the direct route (as the crow flies) between Dannstadt-Schauernheim and Dortmund has been calculated here.
Air line (approximately)
238 kilometers
129 nautical miles