From København H (Copenhagen Central Station) there are frequent train departures to Roskilde. The journey time is about 20-30 minutes, depending on which train you catch.
Planning your trip is easy: Find schedules, prices and purchase your tickets at www.journeyplanner.dk.
Normal one-way tickets start at DKK 84.
Do you want to travel without worrying about traffic zones and ticket prices? With a Copenhagen Card in hand, you get unlimited travel on trains, buses, metro and harbor busses throughout the entire capital region, including to and from Roskilde.