Billie Eilish has "always wanted" to be 18

She said: "18 has been, like, the age I've always wanted to be my entire life and here it is."

And Billie confirmed she has "something in mind" for how she plans to celebrate.

The nominations for the Grammy Awards will be announced in the coming months and the 'Bad Guy' singer could become the youngest woman ever to be shortlisted for the main four accolades, Album of the Year, Song of the Year, Record of the Year and Best New Artist.

However, Billie insists it isn't something she's thought to much about because she thinks it is "weird" when people predict big things for themselves.

She told 'Entertainment Tonight': "Is that true? I still haven't thought about it. I don't think I'll be on stage, you know? I think it's so weird when people think they're going to be huge.

"God, that's so weird. I never in a million years would have thought this s**t would happen. I'm only grateful for it, for real."

But before the nominations are announced, Billie has other things in the pipeline, including serving as the musical guest on the 'Saturday Night Live' season premiere and she's excited, although she admitted it will also be "terrifying".

She said of appearing on 'SNL': "I'm so excited.

"TV performances are like a completely different world. It's so terrifying and so [exciting]. The experiences I've have had always been good, so I'm looking forward to it."