From Billund airport fly to Copenhagen airport. 45min $100. From Billund Lufthavn line 44 bus to Esbjerg st, train to Odense st, then train to Koebenhavns Lufthavn st. 4hrs 52min $79. From Billund drive to Kastrup. 2hrs 55min $60. From Billund taxi to Give st, train to Herning st, taxi to Karup airport, then fly to Copenhagen airport. 3hrs 28min $219.