When measuring for bralettes please use your bust measurement NOT your bra size.
For example if your bust measures 34" you will need a size S.
To work out the cup size measure your under bust then subtract this number from your bust measurement. Each cup size represents an inch difference between the two measurements: A = 1", B = 2", C= 3", D = 4".
So if you have a 34" bust and a 30" under bust you would need a size S with a D cup.
If you are between measurements we recommend sizing down especially if the garment has some stretch in the fabric.
If you need any more help and advice with sizing and fit please get in touch and we'll be happy to help.