The calculated distance (air line) between Cottbus and Doberlug-Kirchhain is approximately 34 miles respectively 55 kilometers.
By car or train, the actual journey to Doberlug-Kirchhain is certainly longer, as only the direct route (as the crow flies) between Cottbus and Doberlug-Kirchhain has been calculated here.
Air line (approximately)
55 kilometers
30 nautical miles