Did you know 80% of women don’t know their right bra size? I don’t blame us, I mean, bra sizing is confusing, and I believe every woman has worn the wrong bra at least once, twice, or many times throughout her life.
But, guess what? It isn’t so complicated, you just need to understand it and we’re here to help you with that.
Here’s how to find your right bra size at home and you only need a tape measure:
Let’s start by acknowledging that our bodies are in constant change and our hormonal cycle can influence the sizing. It is very common that our size goes up when we are swollen. This means sometimes we have more than just one bra size. You can measure yourself at different times of your life to know what your bra sizes are.
STEP 1: MEASURE YOUR BAND SIZE
Put on a sports bra that doesn’t squeeze your breast and that isn’t too loose. You can also wear a regular non-padded bra that fits just right. While measuring yourself, don’t wear any tops or t-shirts
Continue by measuring the contour under your breast in the most parallel way to your bra’s band. Write that number down.
STEP 2: MEASURE YOUR BUST CONTOUR
Place the tape around the fullest part of your bust. Don’t press the tape measure too tight or too loose and be relaxed while measuring. Write it down too.
STEP 3: THE CUP SIZE
Subtract your band size from your bust contour measure. Every inch is one cup size up.
Let’s say your band size is 34 inches and your bust contour is 38 inches. This means the difference is 4 inches, which means you would be a 34 D cup. (example)
However, that isn’t necessarily your right cup size…
Let me introduce you to sister sizes:
(or perhaps you’ve heard of them before)
Sister sizes fit the same size, so even if you see an AA cup or a G cup, yes it can fit you. You will probably think, that some of them are too big or too small and there’s no way for it to happen, but as the band size also changes, it compensates for the cup to fit you better.
So, while you might have a lot of sister sizes, one of them will fit a lot better than the others and that depends on the shape of your bust and how wide your back is.
Following the last example, where the bra size was 34 D, the sister sizes would be highlighted. Go to the column where your bra size is, and all those sizes on that column are your sister sizes. (For example, the sister sizes of 34 D are 42 AA, 40 A, 38 B, 36 C, 32 DD/E, 30 DDD/F and 28 G)
STEP 4: FIND YOUR SISTER SIZE
Sister sizes are your friends here, most of them can be good options for you. But how can you know which one to choose?
Let’s start by understanding how the band and cup sizes work:
BAND SIZE
The larger the band, the wider the cup will be. So, you don’t have to worry, even the smallest cups can fit. The right band is the balance between comfort and support.
As you can see in the next illustration, all of the examples have the same cup size, however, the band changes. If you are very small, then maybe you should focus on the sister sizes that have a smaller band and bigger cup. On the other side, if you have a wide back, then perhaps a smaller cup and a larger band would be more comfortable for you.
CUP SIZE
The smaller the cup, the smaller the underwire. This means that a bigger cup will offer more support and keep everything in its place. But, when it comes to a smaller cup, maybe you will find it more comfortable to wear. This depends on how much you need or want to hold in its place.
In the next illustration, you will see the same band size but with different cups. Just remember that a large cup will compensate with a small band and a small cup will compensate with a larger band.
The most important thing you should keep in mind is how wide are you. You want to be comfortable, but still feel supported, so find the balance and choose by the band, rather than the cup. However, the cup can change the way your breasts look. Here’s an example:
As you can see, the larger the cup, the more it can create a cleavage, but won’t look as voluminous on the sides as a smaller cup would look. Of course, this won’t apply to everyone, as we all have different bodies. Although, it was something we noticed when we were trying on all our sister sizes.
Some helpful tips:
- Go to a store and try on all your sister sizes so you can compare and find your right fit. For better results, try the same bra (style and brand) in different sizes. This will help you notice the differences with more clarity.
- Avoid purchasing online, or at least not until you know your right bra size.
- Your bra should fit perfectly, so when trying them on, play with the straps and sliders until it feels right. If it still doesn’t feel comfortable, try another sister size.
- Your bra shouldn’t be or feel loose. If it does, try a smaller band.
What if I still don’t feel comfortable with any of my sister sizes?
Then, maybe you didn’t try the right style or design for you. What you can do is look for another style and try it on again in all your different sister sizes. Also, you can choose the one that feels better and try it on different designs until you find exactly what you want.
Finding the right bra size is all about trying and discarding. So, don’t be afraid of trying on every bra in the store if you need to.
The right bra style is something more personal, as it depends on the shape and your personal preferences. But that is a whole other topic… Let us know if you’re interested in learning more about it.
We hope this guide helps you understand better how bra sizes work so you can finally find the perfect bra! It’s a complex world at first, but it definitely makes a difference once you comprehend it.
become an official member of our club!
We would love you to be part of our community. There are blog updates, more style tips, quizzes, and other secrets we only share with our insiders!
join at the end of the page
Finding the right bra size can be frustrating, but this guide makes it a lot simpler. Thank you for sharing!
I am very interested in choosing a bra, depending on my breast shape. I have a very wide gap between my breast’s and they are fairly heavy. I’m 64 years old.
My issue is I don’t t have a good bra to measure in. What I have is the wired one and the comfy one that doesn’t hold my breasts up. I do have a longline support bra.
I’m 63 and have lost over 300 pounds. They hang like Walmart sacks with oranges in the bottom!
Can you help me figure out what I should try?
I’d like to order a bra.
I am Rita, my band measurements are 38 and my burst are 50, what is my right size of bra
I measured 35 band and 41 bust. I have a major problem with the back crawling up a lot. I don’t wear underwires I can never get the wire to stay put in the bra. The size I currently use is a 48G. I have lost 25 pounds recently and am 66 years old.
I read the entire article and measured each area as directed. My band measurement is 37. Do I go up to 38?
Hi Elizabeth,
Thank you, I’m happy you read the article.
If you are in between band sizes you can either go up or down. For example, you could try 38 or 36 band. Although, don’t
do this when calculating your cup, for example if you had 39 inches on your bust contour your cup will be a B. Your size would be 38B or 36B, depending the one you feel most comfortable with, your sister sizes would be the ones on the orange and yellow columns where the sizes 38B and 36B are.
If you have any more questions you can send us an email! Great day Elizabeth!
My issue is I don’t t have a good bra to measure in. What I have is the wired one and the comfy one that doesn’t hold my breasts up. I do have a longline support bra.
I’m 63 and have lost over 300 pounds. They hang like Walmart sacks with oranges in the bottom!
Can you help me figure out what I should try?
When I am purchasing online bra that size is L so In number which size will go on me? Bcz when I’m buying it offline i never found correct size
I’m a 40 year old female and I’m a 46dd what should my sister size be
My band is 36 bust size is 42 what is my sister size?
I was a bit lost with the sizing, but with your help it makes sense now, thank you
This make so much sense! But i’m also a little confused. I am a thirteen year old girl who has a bra size of 38 B what would be my sister size?
Thanks so much,
Brooklyn
Hi Brooklyn!
Your sister sizes would be the ones on the yellow column from where your size is located in the graph. For example: 40 A and 36 C.
Hope you find the best size for you 🙂
Dani
I have gone through menopause and have a hard time finding bras that fit and are comfortable. I think this will really help me find the right fit. Thank you.
Band size I am 33, bust is 39. What is my size and sister sizes?
My measurements are 41 around the band and 51 cup around the cups. What size should I buy?
Band size is 33, bust is 39. What are my sister sizes?
Thank you I’ll take your advice up later this evening when I measure myself hope to find my perfect fit. Gone through the menopause body shape has changed so update is need in size.
Also looking forward to your monthly updates.
This is great because sometimes we, as females, don’t know our bust size
Hello,
Did the math 29 1/2″ band size, 34″ bust contour, minus both comes to D cup.
But looking at the sister chart really can’t figure out what the sister size is. Please assist. Thanks
Hi!
Your bra size would be 30 D and the sister sizes are the ones on the blue column (38 AA, 36 A, 34 B, 32 C, 28DD/E).
Hope you find your size!
-Dani
I loved this!!! I am going to go home and measure myself (I think I am a 36 DD) and like you recommended try on every bra within my size and my sister size until I find the right fit.
Thanks for the great advise!
Yes, style can be everything.
Even with small cups I find it critical because I have an east-west orientation. Certain sizes work for me in some styles but not others. Manufacturers should specify which styles are most appropriate for various breast shapes. One size does not fit all!
I’m 59, my sizes have changed. I wore a 44B, but was tight, so went to a 46 C was too loose. Can never find a 46B. Now what?
Hi Rebecca,
This is where you might want to find the sister sizes of 46B. They are the ones on the same yellow column (from the sister sizes chart), for example, you could look for 48A, 44C, 42D, 40DD sizes. Which are similar but some change in cup and band size. It would be depending in what you need, more space in the cup or a larger band.
Hope you find the best size for you!
-Dani
This really helped me! I am a twelve (turning 13) year old girl and I was curious to find my size because I hadn’t done that before and I am also looking into different kinds of bras so this really helped for when I go shopping! 🙂
Oh my goodness Karyna! You made our day! I’m really happy this was helpful for you and for your bra shopping journey 🙂
Me encantó, por fin encontré la forma correcta de buscar mí talla, tengo 64 años