How to use the chart

In the chart, find your size, then look at the sizes directly to the left and right of your size, they're your sister sizes. If you're on mobile and the chart is difficult to see, try downloading the photo to your phone or consider using desktop! 

Eg. for a 32C:
the sister sizes are 30D and 34B

Sister sizing is a technique used in the lingerie industry when they just can't find the right bra for you with your natural size. Sister sizes are not the same as perfectly fitting bras, but you could give it a go if you're struggling to get a bra that you like in the size that you need. 

If you go up a band size, then you come down a cup size. Likewise if you go down a band size, you come up a cup size. So if a bustier you'd like to buy isn't in your size, check to see if it's one of your sister sizes and it will still theoretically fit you.