What are bra sister sizes and how do I use them?

So, you finally got yourself professionally fitted to learn your size. No more bras that dig in, ride up or just don’t do your body justice as you finally wear correct fitting undergarments. Woohoo! But, as you probably know, not all bras are created equal (fitting).

The best news is, rather than ditching a style altogether because your regular size doesn’t feel quite right, or you want to try a new, different style of bra, you’ve got some options up your sleeve. Secret weapons if you will - bra sister sizes.

What is a bra sister size?

Sister sizes are alternate sizes that surround your bra size where the cup volume remains the same, even though the band size and cup letter change. Knowing your sister sizes can help you find your best fitting option when buying bras that run slightly smaller or larger than normal. It’s all a matter of bra conversion. That is, working out what your bra size equivalent is. But be warned, this little hack may change your life!

How do I find my sister size?

Let’s say you wear a 12D in most cases. For some bras with a slightly larger fit, you could opt for a 10 band. But, don’t simply swap your D cup for a D cup. When you go down in the band fit you need to go up in the cup size to keep the cup volume the same. So, a 10DD is a sister size to a 12D. It works the other way when you go up in the band size, from 12 to 14, while going down in the cup to a C. 14C is the other sister size for a 12D. Use our Sister Sizing Chart to find more. 

Think you’ve got it?
Sister Size Example

If you’d love a new gorgeous Minimiser bra in your life, for example, different styles within the range fit differently. So, you may need a different size in the fuller coverage True Shape Sensation Minimiser style to what you would in more of a balconette or Sheer Minimiser style. Amourette bra styles also vary greatly in the range, from the Amourette Wired Padded Bra to the Spotlight Balconette. Once you’re armed with your sister sizes though, you’ve got options up your sleeve to help you find the perfect fit.

How do I check for best fit?
Bra Size Calculator

Finding your sister sizes and the perfect fit shouldn’t be difficult. We offer expert in-store bra fitting to help you find the bra that gives you ultimate confidence. We also have fit advice and tips you can follow, such as interactive size charts and a bra size calculator. Some helpful general tips are that if your breasts spill out of the cups or wires dig in at the sides, you may need a larger cup size. A band that rides up at the back is too big and you may need a smaller back size. If a bra is uncomfortable in any way, it’s not your perfect match.

Feel confident every day

Remember, a well-fitting bra is the fastest way to body confidence, every day. Don’t settle for discomfort or unflattering garments that dig in. Get professionally fitted and follow our fit guidelines for lingerie and a look you’ll love. With over 136 years’ experience, Triumph are the experts in the creation and fitting of beautiful lingerie.

Is it time to treat yourself to some new special pieces?