Bra sizing is a kind of magic, where one bra size can have many Sister Sizes.
Sister sizes are groups of bra-size equivalents that are related by cup volume. Where your specific bra size might have a number or related sizes. This means that if you can't find your favourite style in your size, you might be able to choose your sister size.
You don't need to wait to use this trick to find a bra in a particular size - if your fave has sold out.
If you are happy with the cup size that you have and the way that it fits. But the band size feels a little firm - you can go up a back size to have a bit more room - and use the sister size to keep the same size cup! For example, if you fit a 12D in the cup- but feel like the band might be a bit too tight you could move up to a size 14C to get a bit more room in the band and keep the same cup.
Alternatively, if you feel like the band is a little loose but the cup fits, and you would like a more firm fit. Size down in the back, just remember to go up in the cup size to get the same size cup. For example if you are wearing a size 16C, but feel like the band is a little loose you can go down a back size to a 14 and up a cup size to a D cup.
If you go up a band size, then you go down a cup size.
Or...
If you go up a cup size, then you go down a band size.
Using the table below find your size - all sizes on the same row are your sister size. For example, a 12D has a sister size of a 10DD, 14C, 16B or 18A.
8A | 10AA | - | - | - | - | - | - | - | - |
8B | 10A | 12AA | - | - | - | - | - | - | - |
8C | 10B | 12A | 14AA | - | - | - | - | - | - |
8D | 10C | 12B | 14A | 16AA | - | - | - | - | - |
8DD | 10D | 12C | 14B | 16A | 18AA | - | - | - | - |
8E | 10DD | 12D | 14C | 16B | 18A | - | - | - | - |
8F | 10E | 12DD | 14D | 16C | 18B | - | - | - | - |
8FF | 10F | 12E | 14DD | 16D | 18C | 20B | - | - | - |
8G | 10FF | 12F | 14E | 16DD | 18D | 20C | 22B | - | - |
8H | 10G | 12FF | 14F | 16E | 18DD | 20D | 22C | - | - |
8I | 10H | 12G | 14FF | 16F | 18E | 20DD | 22D | 24C | - |
8J | 10I | 12H | 14G | 16FF | 18F | 20E | 22DD | 24D | - |
- | 10J | 12I | 14H | 16G | 18FF | 20F | 22E | 24DD | 26D |
- | - | 12J | 14I | 16H | 18G | 20FF | 22F | 24E | 26DD |
- | - | - | 14J | 16I | 18H | 20G | 22F | 24F | 26E |
- | - | - | - | 16J | 18I | 20H | 22G | 24FF | 26F |
- | - | - | - | - | 18J | 20I | 22H | 24G | 26FF |
- | - | - | - | - | - | 20J | 22I | 24H | 26G |
We recommend that you get fitted once every 12 months. However, if you notice your body is changing you should get professionally fitted, regardless of how recently you were fitted. A woman's body can change due to puberty, pregnancy and due to fluctuations in weight. Wearing the correct bra size promotes good breast health, it’s important to keep an eye on any changes in breast size.
If you think it’s time to start shopping for your daughter's first bra, we’ve got you covered. We recommend popping into your local Bendon store for a professional fitting. If you’re interested in more information, check out our guide The First Bra for Beginners: How to buy your daughter her first bra.
A bra fitting is a super quick way to find out your bra size. One of our lovely retail team members will measure you, have a quick chat about your favourite bra styles and then complete a fit check. If you want to know more about what happens at a bra fitting, check out our guide.
Gone are the days of wearing the wrong-sized bra! Take our fit finder quiz to find your perfect fit.
Our Insider Blog is a wealth of information on helping your to find your best fitting bra.