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bra sizes

Are you having trouble figuring out your bra sister size?

Finding a bra that fits well is challenging as it is and converting the bra into its sister size can be even more difficult.

While we typically recommend becoming familiar with a lingerie brand before trying sister sizes, sometimes a sister size can provide a better fit than the size you normally wear.

This is why it’s so important to understand what sister sizing is and how to find your bra sister size when shopping for bras.

What is a sister size?

For those of you wondering, the cup volume of a sister size is closest in fit to your true bra size. For example, if you normally wear a 34D in bras, your sister bra sizes are 32DD and 36C.

Sister sizing is useful to know when you’re buying bras from a brand that runs small or big.

It also helps when you find that a pretty bra that doesn’t come in your true size (ie. you wear a 34DD, but the style is only available in A-D cup sizes).

As someone who wears a larger cup size, it still baffles me that so many brands think bra sizes begin at a 32 band size and stop at a 36 band size or end with a C or D cup. What are the rest of us supposed to do? Go braless?

Related: What Are Bra Sister Sizes?

Sister Sizing Tips

Though some of us have found bras that fit well in sister sizes, please remember that the fit will likely be different from the size you typically buy.

Even if you’re sizing down in the band and up in the cup or up in the band and down in the cup, the band size may end up being too snug (uncomfortable) or too big (unsupportive).

This is why it’s best to try on sister size bras before purchasing. If you’re shopping online, be sure to check the size charts, product reviews, and the store’s return policy.

Nothing is worse than getting a bra in the mail that doesn’t fit and having to go through the hassle of returning it.

Here’s how to find your bra sister size with our simple chart:

Since many of us have had trouble with sizing conversions, we created a chart to help you find your find your bra sister size and easily.

As an added benefit, our chart also includes built-in UK to US cup size conversions, so you won’t have to convert them yourself. Though sister sizing might seem crazy at first, it gets easier over time. We hope this chart helps you easily find your bra sister size.

1.  Locate your bra size on the chart.

2.  The bra size directly above your bra size is your sister size with a smaller band and bigger cup.

3.  The bra size directly below your bra size is your sister size with a bigger band and smaller cup.

Bra Sister Size

Conversion Chart


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Related: Bra Sister Sizing Frequently Asked Questions

We Highly Recommend

Whether you’re shopping for new everyday bras or lingerie for a special occasion, it’s always a good idea to seek out a second opinion. We know how hard it is to find bras that fit well and feel good, especially when you’re doing it on your own. If you’ve ever felt unsure about your bra size or you just don’t know where to go to find good bras, it’s time to let a bra fitter help.

Many specialty lingerie boutiques offer bra fittings. Their expert bra fitters will take the pain and frustration out of bra shopping and do all the work for you. Even better, their product knowledge can save you time and money. Plus, they know where all of the best bras are hiding.

If you’ve struggled with finding bras in the right size, it’s time to make a change. Visit our specialty store locator to find a store near you and schedule an appointment.

Happy bra shopping!

Featured image lingerie:
Parfait Lucie Bra P5202 | Parfait Lucie Brief P5203 in Mood Indigo
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Published by

Katie Donnelly

Katie Donnelly is a full-time freelance writer, content manager, and founder of Katie Rose Creative. An experienced bra fitter, Katie has helped hundreds of people shop for lingerie. Her favorite bra is the Sandrine Plunge Longline Bra.

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