What bra sizes are sister sizes?

When you shop for underwear’s that match your outfits, you want to get something that fits and gives you the self-confidence you need. There Is a limited amount of sister bra sizes that might fit well with the occasion you plan to attend. The bigger cup can sometimes have this defect. They might be big in size at the back while small in cup size. This sometimes lead to confusion and a ride up at the back.

So What bra sizes are sister sizes? There Is a limited amount of sister bra sizes that might fit well with the occasion you plan to attend.

Short Answer

Sister bra sizes are the same as you will find the same cup volume, but a different band size. With this, your breast can easily fill a sister bra cup even when the back sizes and cup letters seems to be different hereby holding the same boob amount. It’s a one size fits thing.

so your breast do not have to be loose or let your breast get saggy.

What’s the point of sister size bras

The point of sister bra sizes is to give you an opportunity to get a bra which is a bit smaller or larger than normal for you.

A poorly worn bra affects your health as shown by experts. And when you want accuracy, the sister sizes are quite accurate. For example, A  38C, is in the family of : 30F, 32E, 34DD, 36D, 38C (your size), 40 B. this means you will need a sister size of 36D and 40B, since they give you the same cup despite different band size. According to the experts who did a research article here1 , Sister Sizes is an equivalent bra size which fits your measurements.

Sister Size Up Vs Sister Size Down

The sister Bra sizes do come with the same cup volume, although their band sizes and letters might be different.  

You can wear sister sizes that are similar since it fits the measurements. This sister size up and sister size down may be confusing but it’s an easy thing to do as we shall explain more in this article.  

There are two parts of a bra, the band size, and the cup size. With the band, you typically measure numbers 32-40 inches or cm around the rib cage.

The cup size, is the alphabets or letters we assign to cup volume.

The cup letter volume is based on the pairing with the band size. For example, when you get a  38DD it is actually a cup larger than a 36DD, which itself is bigger than  a 34DD,

You might need to change a cup letter when there is a band size change as the volume will remain the same.

There is a simple rule you can follow to achieve this and I will try to explain it further. Whenever you move up one place, then move down the cup size to retain the volume.  and while moving down the band size, move up a cup size. Let say we have a 32F band sister bra, a leap upwards would mean a 34 E. when it’s time to step down , it goes to 30FF.   

Bra Sister Size Chart

sister sizes chart

Use the sister size chart as a reference table for your sister bra sizes

The table above : this is a size chart showing the equivalent bra sister sizes from 28D to 40K. read this chart diagonally to get the sister sizes from it

Take some time and let this sink in. when you get hold of it, it starts becoming easy to do every time. its been proven from experience that bras are foundational garments. A lady has been putting on a 36H bra every time. She never know her true size was a 38E. she was happy to find out.

do you think sister bras work?

Have you ever wondered how that’s possible that sister bras could work since they have different cups? Some of the popular UK sizes are FF, G, GG cup size.

They might sometimes seem big when you believe a DD is the largest size.

 bra sister sizes that are the same cup size- these are the 34FF, the 32G and your 36F, since you are definitely making adjustment to the cup to back ratio.  

using our sister cup size chart

When you have decided you need a fitted bra, then use the sister cup size chart we have placed here.  Every rows in the table shows the sister bra size units and they are well arranged as a family. For a 40DD, here are your sister sizes are 38E, 36F, 34FF, 32G, 30GG, and 28H.

If you don’t have a sister size? What happens

If you really need a fitted cup volume bra and the sizes you have tested aren’t what you are confident in wearing, the its time to DIY your sister size using out charts. Here.

This can be easily worked out by taking a closer look at the chart here. When moving down the sister bra size chart by a two, or three then move up the cup size by a two, or three and repeat the same steps when move up the chart.

It night seem a bit tricky at first but that might be all you need.

How can you find your Bra Equivalent Sizes

We have so many equivalent bra sizes but I’m not sure that many are aware of hem. When they do, they might not know how to calculate or get these measurements. This can be done manually or using the calculator.

To find your size, check each row and see them as a family of sizes.

What bra sizes are equivalent?

What Is Sister Sizing?

Bra SizeSister Size UpSister Size Down

When the cup volume fits but the band is oversized, make some adjustments in the opposite directions. When it seems like the band is small, move up a size and down a cup size.


Esther David
Esther David

As a blogger and business owner, i have 7 years experience in fashion, and beauty and this site about lingerie’s and women underwear’s with Using and selling different clothing brands.

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