XS = Bust size 74cm – 78 cm under the bust. Bust size 84cm – 88 cm top of the bust. S = Bust size 86cm – 90 cm under the bust. Bust size 97cm- 101 cm top of the bust. M = Bust size 86cm – 90 cm under the bust. Bust size 100cm – 104 cm top of the bust.