The calculated distance (air line) between Nykøbing Sjælland and Slagelse is approximately 38 miles respectively 61 kilometers.
By car or train, the actual journey to Slagelse is certainly longer, as only the direct route (as the crow flies) between Nykøbing Sjælland and Slagelse has been calculated here.
Air line (approximately)
61 kilometers
33 nautical miles