Jessie J has confessed she feels "childish" singing her smash hit Price Tag.

The British star shot to international fame in 2011 when the track, her second single release, topped the charts in four countries and broke into the Top 30 of the Billboard Hot 100.

But she admits she is now embarrassed to perform it live as she was 18 years old when she wrote it and she has since grown out of the feelgood tune.

Jessie tells Hello! magazine, "I'm 25 now. I was 18 when I wrote my first album. However much I love Price Tag, I feel a little childish singing it now, and that's okay. Everyone grows, learns, evolves."