Bra Sister Sizes - Upbra

Maybe your like

SHOP ALL
SHOP BRAS
SHOP BIKINIS
BOTTOMS & ACCESSORIES
HOW UPBRA BRAS & BIKINIS WORK
PRODUCT Q & A
VIDEO REVIEWS
CUSTOMER SERVICE
- PRODUCT FAQ's
- SHIPPING FAQ's
- Contact Us

Bra Size Finder

Exchanges and Returns

Get Answers / Chat

Insane cleavage is all yours with an Upbra t-shirt bra

BRA SISTER SIZES:

The Bra Secret You Should Know About

If you've found that finding your right bra size is a frustrating process, there are some sizing hacks that can make finding your perfect fit much easier. One of the most effective of these is the use of “Bra Sister Sizes”. You may be unaware that every bra size has several "Sister Sizes"- these are sizes which have an equivalent cup capacity, despite the letter of the cup size being different. Knowing your sister sizes can help you find your best fit when buying bras that run smaller or larger than normal. It’s a common misconception that the larger the cup size, the larger the bra, no matter what the band size (i.e. a 32F is larger than a 36B, a 34C is larger than a 38A, etc). However, this is not the case. During the bra manufacturing process the same exact bra cup may be paired with different band lengths to create multiple bra sizes. For example, the same exact cup is used to make 38A, 36B, 34C, 32D, AND 32DD bras! The reason for this is that within each cup size (A, B, C, D, DD, etc), as the band size increases, the cup size also slightly increases even though the letter does not. For example, a 34B bra and 36B bra will not only have different lengths, but the capacity of the cups will also differ. Once you understand that there are equivalent “sister sizes” to your own bra size, it can help you solve any bra fitting issues you may have.

Bra Sister Size Size Comparison Chart:

Each row shares the same cup size and each column shares the same band size. Sizes in black are sizes we make. Sizes in light gray are sizes we dont make.

30 BAND SIZES
Sister Size DOWN	Current Bra Size	Sister size UP
28B	30A	32AA
28C	30B	32A
28D	30C	32B
28DD	30D	32C

32 BAND SIZES
Sister Size DOWN	Current Bra Size	Sister size UP
30B	32A	34AA
30C	32B	34A
30D	32C	34B
30DD	32D	34C
30DDD	32DD	34D
30F	32DDD	34DD

34 BAND SIZES
Sister Size DOWN	Current Bra Size	Sister size UP
32B	34A	36AA
32C	34B	36A
32D	34C	36B
32DD	34D	36C
32DDD	34DD	36D
32F	34DDD	36DD

36 BAND SIZES
Sister Size DOWN	Current Bra Size	Sister size UP
34B	36A	38AA
34C	36B	38A
34D	36C	38B
34DD	36D	38C
34DDD	36DD	38D
34F	36DDD	38DD

38 BAND SIZES
Sister Size DOWN	Current Bra Size	Sister size UP
36B	38A	40AA
36C	38B	40A
36D	38C	40B
36DD	38D	40C

Common Fit Problems and How to Solve them Using Sister Sizes:

If your cup fits but you need a different band size.

To change your Band Size and keep the same Cup capacity, remember that the 36C with cups that fit you (for example) has the same cup capacity as the 34D with the smaller band size and the same Cup capacity as a 38B that has a larger band size .Getting your best fit will require both the band size AND cup size to change. For another example, if you are wearing a 34B bra and the band is tight but the cups fits well, instead of going up to a 36B, you should choose your equivalent sister size, 36A.

If your band fits but you need a different cup size.

If your band fits great but your cups are too big or too small, keep the band size the same and just adjust the cup size based on your needs. For example, if you are wearing a 34B bra that fits in the band but has cups that are too small, you should choose a 34C.

If both your band and cup don't fit.

If you both the band and the cup are a bit loose, the band should go down and the cup capacity should go down too. Remember that with a smaller band bra, the same Letter cup size is going to be smaller. For example, if you are wearing a 34B that is too loose in both the band and the cup, try a 32B. It's a smaller bra, so the same Bcup in a 32 is smaller than a Bcup in a 34. If you have a 34B that is too Tight in both band and cup, get a bigger band, and remember that in a bigger bra the same Cup Letter is bigger too. So a 36B is bigger in band and cup. By knowing your correct bra size, as well as what your sister sizes are, you will be able to choose the best option to give you a perfect fit. ! For more sizing help, international size conversions, or to try our new mobile sizing app, please go to our Sizing Help page by clicking here.

YOUR SECRET WEAPON FOR AMAZING CLEAVAGE

Luxury bras that enhance, lift, and flatter your curves

Now there's a better way to Get Your Bra Size

A new way to get your bra size measurements. After a year of testing with over 8,000 women, and six months of beta testing in the app store, we're introducing the Upbra Mobile Bra Size Calculator- the simplest bra size calculator ever. Use your phone to get your bra size in just a minute. Since you will only need it once, you don't need to download anything. Just run the Upbra Mobile Bra Size Calculator instant app through your phone's web browser. No measuring tape, no camera, no memory, no downloading.

Try the App If you use the Upbra Mobile Bra Size Calculator to determine your size, we will guarantee your fit. This means that if you order an Upbra bra in the size given to you by the app and for any reason it does not fit, we will reimburse you your return postage up to $8.95 USD for your return until you get the correct size fit.