Iggy Azalea, 33

Christina Aguilera, 43

Demi Lovato, 31

Tyra Banks, 50

Katy Perry, 39

Lady Gaga, 38

Nicki Minaj, 41

Beyonce, 42

Britney Spears, 42

Taylor Swift, 34

Miley Cyrus, 31

Ciara, 38