What is Sister Sizing?

If you’ve ever struggled to find a bra that fits your unique shape, you’re not alone. I want to teach you a trick every woman should know that can help make bra shopping a little easier – sister sizing! The one thing I always tell clients before I fit them is that whatever size I fit them as isn’t set in stone – they may have one true size but may be another two different sizes depending on the brand, style, fit of the bra and of course, their unique body shape.

So what actually is sister sizing?

It’s a group of sizes that are the same cup volume but different band sizes. For example, someone who wears a 34C could also wear a 32D and a 36B depending on if they want a tighter or looser fitting bra but the cups will fit the same. Cup sizes aren’t stagnant so when you go up and down band sizes, your cup size changes with it.

You’re probably wondering why you need to know this so let me get to it:

Let’s say you try on a 34DD and the cups feel good and fit well but the band feels a little too snug for your liking. We want to keep the cup volume but go up a band size so we would want to sister size UP to the 36D. The band size has gone up so you’re a little more comfortable but the cup size has come down to ensure the volume of the cup has stayed the same.

Alternatively, if the band is feeling a little too loose and not supportive enough, we would sister size DOWN to a 32E. The band size has gone down but the cup size has increased to compensate for the volume.

You can use the chart below to discover your sister size:

So what if my normal bra size is sold out. Can I buy another size?

There’s nothing more frustrating than going to buy that gorgeous bra you’ve had your eye on only to find it sold out in your size. If your size isn’t available or if a certain style isn’t quite fitting right, trying a size within your sister size range is definitely an option to consider but a word of warning – sister sizing isn’t a fail safe solution and a good fit should never be sacrificed! It is certainly a good trick to know as sometimes it really can help you find the perfect fit. But if it doesn’t work, it may be that particular style just doesn’t suit your body shape and that’s okay!

The one thing to remember is that all brands and styles of bra will fit slightly differently, so it’s always a good idea to try a few different sizes to find what works best for you. The most important thing is that you listen to what your body is telling you and that you feel comfortable. Never settle for something that doesn’t make you feel good – a well-fitting bra that fits well, looks and feels good can make you feel like you can take on the world!