What’s Sister Sizing you ask? Well, it’s the answer to (some) of your bra troubles. And it’s easier than you think! Armed with this knowledge, you’ll be able to find even more bras to fit you. Sound good? Let’s start!

In order to find your sister size, all you need to do is take your bra size and either:

Add a cup size, minus a band size

OR

Add a band size, minus a cup size

So if you’re a 34F, you can either try a 32FF, or a 36E.

Still confused? Don’t worry!

The reason why you can do this is because by following this formula, the underwire length is the same, as well as the neck edge. The only thing that changes is the length of the underband. Luckily, all our bras come with at least 3 sets of hook and eyes so you can adjust the band to fit you better.

To make things even simpler, we’ve made a chart so you can easily find your sister size. All you need to do is find your bra size, and look along the same row to see which sister size will be a suitable fit. We don’t recommend going any more than 1 size up or down however, as the band will be too loose or too tight!

Aus Sister Sizes

 For more help on sister sizing, check out our video!