The calculated distance (air line) between Nykøbing Sjælland and Roskilde is approximately 25 miles respectively 41 kilometers.
By car or train, the actual journey to Roskilde is certainly longer, as only the direct route (as the crow flies) between Nykøbing Sjælland and Roskilde has been calculated here.
Air line (approximately)
41 kilometers
22 nautical miles