One Direction top Billboard's 21 Under 21 list

One Direction have been crowned 2013's most powerful pop stars under 21.

The Best Song Ever hitmakers - Harry Styles, Niall Horan, Liam Payne, Louis Tomlinson and Zayn Malik - have topped Billboard magazine's annual 21 Under 21 list, which ranks the young artists based on factors such as music sales, touring and social media influence.

Justin Bieber trails in second place, while Miley Cyrus is at three, followed by Ariana Grande and rapper Earl Sweatshirt in fourth and fifth place, respectively.

Scotty McCreery, Austin Mahone, Cody Simpson, British singer Cher Lloyd and hip-hop star Chief Keef are also featured on the new countdown.