Sister Sizes: What Are They and Why Do They Matter?

If you have been a consumer in the bra market for awhile, there is a good chance you have heard of sister sizes. But what exactly are they? Does it mean that if you go up a cup size and down a band size, the bra is the same size as the one you wear? Is it just a marketing ploy made up by the corporate world? What is the purpose of bra sister sizes? We are going to clear up all those questions and more!

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What Are Bra Sister Sizes?

Sister bra sizes, also known as sister sizes, are bra sizes that share the same cup volume but have different band sizes. This means that a woman who wears a 38C, for example, may also be able to wear a 36D or a 40B. Understanding sister bra sizes can be helpful for women who are having trouble finding a bra that fits properly, or for those who are in between sizes. When it comes to the fit of the bras, women absolutely have preferences, even if 2 women wear the same size, they can prefer for their bras to fit differently.

It’s all about comfort and what makes you feel the best in your own skin. And that is where bra sister sizes can be really helpful. They can allow for micro adjustments when it comes to bra sizes.

The concept of sister bra sizes is based on the fact that band size and cup size are not always directly proportional. A woman’s band size is determined by measuring around her ribcage, just under her bust, and then rounding up to the nearest even number. Her cup size is determined by measuring around the fullest part of her bust and subtracting the band size measurement. So, for example, if a woman’s band measurement is 36 inches and her bust measurement is 38 inches, her cup size would be a B (38 – 36 = 2 inches).

How to Calculate Your Sister Bra Sizes

Just because a woman’s band size is 40 and her cup size is D, it does not mean that she will always fit into a 40D bra. This is where sister bra sizes come in. By understanding the relationship between band size and cup size, a woman can try on bras in different band sizes but with the same cup volume, in order to find the best fit.

Bra sister sizes

For example, if a woman tries on a 36B and finds that the band is too tight but the cups fit perfectly, she may want to try on a 38A. The 38A has the same cup volume as the 36B (B cup), but the band is two inches larger. Similarly, if a woman tries on a 38B and finds that the band is too loose but the cups fit perfectly, she may want to try on a 36C. The 36C has the same cup volume as the 38B (B cup), but the band is two inches smaller.

Why Are Bra Sister Sizes Helpful?

The concept of sister bra sizes can also be helpful for women who are in between sizes. For example, if a woman’s measurements fall between a 36B and a 38B, she may want to try on both sizes to see which one fits best. If the 36B is too tight but the 38B is too loose, she may want to try on a 37A or a 37C. These sizes have the same cup volume as a 38B (B cup), but the band is one inch smaller.

It’s important to note that sister bra sizes are not always an exact match and not all brands or styles may fit the same. The best way to find the right size is to try on multiple sizes and styles. It’s also important to note that a woman’s size may change over time due to weight gain or loss, pregnancy, or other factors, so it’s a good idea to get measured regularly to ensure that you are still wearing the right size. Any time you are going to buy a new bra, it’s always a good opportunity to remeasure to make sure you are purchasing a bra that fits properly!

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Possible Downfalls to Sister Sizes

Another thing to keep in mind is that, while sister sizes can be a helpful tool, they may not provide the same level of support and lift as a bra that is the perfect fit. A bra that fits properly will have the band parallel to the floor, the straps will not dig into the shoulders and the cups will fully encase the breasts without any spillage or gaping. So, while trying different sister sizes may be helpful in finding a bra that is comfortable and easy to wear, it’s still important to find a bra that fits properly to provide the best support and lift.

It’s also worth noting that not all brands and manufacturers will use the same sister size chart, so it’s important to check the size chart provided by the brand or manufacturer before trying on a sister size. Additionally, some brands may offer extended sizes, which can be helpful for women who have a hard time finding bras in their size.

When trying on sister sizes, it’s important to pay attention to how the bra feels on the body. A well-fitting bra should be comfortable and not cause any discomfort or pain. It should also provide adequate support and lift for the breasts. If a bra feels uncomfortable or does not provide the right level of support, it’s best to try a different size or style.

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Wrap-Up

Sister bra sizes can be a helpful tool for women who are having trouble finding a bra that fits properly or for those who are in between sizes. But it’s important to remember that they may not provide the same level of support and lift as a bra that is the perfect fit. It’s also important to try on multiple sizes and styles, and to pay attention to how the bra feels on the body. With the right size and style, a woman can look and feel her best in a comfortable and supportive bra.

In summary, sister bra sizes are bra sizes that share the same cup volume but have different band sizes. Understanding sister sizes can be helpful for women who are having trouble finding a bra that fits properly or for those who are in between sizes. It’s important to keep in mind that sister sizes can be a helpful tool, but they may not provide the same level of support and lift as a bra that is the perfect fit. It’s also important to remember that not all brands or styles may fit the same, so it’s important to try on multiple sizes and styles to find the right fit.