The cheapest way to the airport. Nothing listed is quicker.
M2 metro
M2 · Copenhagen Metro (Metroselskabet), on a DOT ticketPickup, hours & luggage
Boards at. Any M2 station towards Lufthavnen — Kongens Nytorv, Nørreport and Christianshavn among them
Buy a DOT three-zone single, kr. 30 — not the four-zone one at kr. 40, which the machine will also sell you. Two children under 12 travel free with a ticketed adult; under-16s pay about half. A City Pass Small, kr. 100 for 24 hours, beats singles from the fourth ride.
Luggage. Driverless trains with open floors; busy at peak.