Bra size caculators~ Why you shouldn’t bother

Any woman who has ever worn a badly fitted bra has probably tried to find their “correct” bra size online through a calculator. She is probably as frustrated as the woman who tries to find her size online so she can order a bra, hoping it fits because she cannot try it on in stores.  Well, bra size calculators just do not work!! They can give you an estimate, but each one will vary depending on the manufacturer. To illustrate the differences, I’ve selected some calculators, put the requested measurements in each, and was given a response.

85b  Results- US/UK 30F. Umm…. US and UK sizes are totally different, and this size is much too small.

Linda’s Online Results- 30J. No US or UK size. It is actually US sizing which would be a UK 30GG.  What is interesting about this calculator is that many ladies with a larger underbust measurement then I have will find it accurate. But the calculator does not have anything for a smaller ribcage. Anything smaller than a 30″ ribcage is a 30 band. My ribcage is 26″ so it does not make sense that I would wear a bra band the same size as a woman who has a ribcage 4″ larger than mine.

Mr. Bra Results- 32H or larger. WTF does that mean? Really or larger? And a 32 bandsize? This calculator does not even acknowledge that bras are available smaller than a 32 band.

Vassarette  Results- “Measurement #1 is too small for the measurement you gave for measurement #2.”  So I guess my boobs are an impossible size.  And this is a common US brand for low-cost bras available at stores like Walmart.

Curves and Corsets Results- 26H. The closest one yet, but still not right. Notice that they do not add any inches to the underbust measurement.


So as you can see, each of these has a very different result. I used the same measurements in every calculator, 26″ ribcage/underbust, 37″ fullest bust, and in the case of the first one, 30″ over the breast. And this is not even looking at some of the more ludicrous sizing systems such as Victorias Secret. So obviously a bra size calculator is not the way to go to find your bra size. So really what is?  You could use these as a starting recommendation, but the difference in sizes is so large, you’d never find a correct fit. So my next blogs will be sizing with other methods commonly used, underbust measurement only to find size, sizing by eye, and sizing by instructing the wearer about their bra and how it could and should fit better. And maybe while we are at it we can throw in some sizing mistakes commonly made by women in the US.


  1. I always have trouble with calculators… even the “good” ones are really only useful for an approximation!

    Out of curiosity, how far off is the last calculator for you? It gave me my usual bra size (28GG) when I entered my measurements, and from your measurements, it sounds like a 26H is about what you might wear…

    • It seems to be about 1 cup size off. Ideally I’d be in a 26HH. I am desperately researching for tighter 28’s and even 30’s. I have a few 30Gs in the Affinitas Parfait line that are slightly too small, I’d like a 30GG which they do not make. I have a Freya on order in a 28H, hoping for a tighter band and a few of the Gorgeous line from Debenhams as recommended by a few posters on a Busts for Justice post.
      So I’m really trying to get all figured out and get in a proper size. I am unusual when it comes to fitting, I want to write a blog about it tomorrow. It could make others hate me or realize that there are more challenges for different types.

      • Have you seen that The Big Bra Bar is going to offer a trial 26 band bra in March? ( You might want to try it out!
        Also, Ewa Michalak ( will do 26 bands by custom order.
        I understand the struggle – it’s hard enough for me to find good 28 band bras, and even some of those are too loose on me 😦 Freya tends to be a little loose for me, for example.

      • Not to brag, but as soon as I saw it on their Facebook page I posted a blog about it. I was so stinking excited! I watch their Facebook page for updates, I’ll be a preorder if they’ll make a 26HH. I’m worried they’ll stop at an H like they do in their other band sizes. I have the yellow polka dot bikini that I need to post a review for. It’s very cute!
        Panache is supposed to make a 26 band for the 2013 spring collection. I not holding my breath for fit, their cups tend to run too wide for me.

  2. Oh, I hope they don’t stop at H! I remember seeing several people comment that they would like an HH or bigger, so hopefully they’ll listen!
    Panache tends to be too wide for me as well, but at least it will be another 26 option, and maybe other companies will follow!

  3. Becca

    OMG I’m so glad I found your blog! It has been a challenge to find bras. I also have a breast augmentation and I measure 26 inches under my bust, and 37.5 to 38 inches around the fullest part of my bust. I read all your reviews on Bratabase. ^_^

    • Hi Becca! I’m glad you have found my blog useful. 🙂 I’m actually measuring almost exactly the same as you are now, between 37.5-38 inches. It’s amazing how boobs change. So it sounds like you and I are boob sisters. 😀 Just let me know if you need help. Helping ladies like you (and me) is why I started this blog!

      • Becca

        Thank you. After reading your posts about the Affinitas Parfait bras I purchased a few of them! So far I have to say I love the Jeanie bra (30FF) better than my Freya Deco (28G). In both of these the cups are a wee bit small and in the Jeanie I could have gone with a G, and in the Deco I could have used a GG but they don’t make that cup size in the Deco at that band size. I am on the hunt for the perfect T-shirt bra, but have yet to find it. The Jeanie comes close, but it’s not perfect. I find that the T-shirt molded cup bras just don’t lay right across the top of my boobs. I’m going to say it has to do with the shape of my high profile implants. I’m also on the hunt for a molded strapless bra. Do you have any suggestions? I just purchased a Fantasie (4530) in a size 30F, but the cup was way too small so I need to exchange it for a larger cup size.

      • I have issues with the molded style bras as well. I don’t have any natural tissue of my own, so I do best with a bra that molds to me not needs my breast to mold to it.
        Don’t give up on the Deco yet, they are releasing a 28GG this summer, June I think. With the Affinitas bras, the Casey is similar to the Jeanie but different at the same time. I have measurements for both listed on Bratabase in a 30G. I don’t remember which one, but one is looser then the other in the band.
        I’ll look into a strapless style and get back with you. If you can wear some 30 bands with your ribcage size you can try the Taylor in a strapless. It’s a version of the Deco. I’ll see if I can find anything in around a 28GG that ma be worth trying. I’m on the hunt for a strapless too, but haven’t had much luck.

  4. Becca

    Really? A Deco in a 28GG? I’ll be all over that! The 28G does fit, but I think my boobs giggle out of the cup just a little, so I get a slight slip of the nip and have to readjust and as the day goes on and I have to then hook it on the tighter hooks because the band stretches out. I have a love-hate relationship with the Deco. >_> *Sigh* To be honest I think I’m between a G and a GG. In some bras if I go up a cup I get the over the boob airspace where the strap meets the cup and if I go down a cup the bra cuts across creating the dreaded quadra-boob.

    • Hey Becca, just getting back with you about strapless bras. I can only find 1 that comes in a size range that may work for you, the Panache Evie. It is not a molded cup and the cups tend to be wider. So I don’t really think it would work for you. With HP implants you want a narrow cup. The Deco strapless does come in a 28G (in a GG starting at a 30 band) and the fit is actually quite different then the regular Deco. If you can find it at a website that offers returns, it may be worth trying for you. I’ll keep looking and I’ll let you know if I find anything.
      As for the problem with the straps of your bra not sitting flat on your chest, most likely that is from the profile of your implants. HP implants have a lot of projection (I have the style 45 which is like an UHP, so I know how you feel) so sometimes the straps will lift like you describe if the cup depth isn’t enough for your projection. Sometimes when you go up in cup size the width of the cup increase and the projection decreases, giving the cup additional volume but not in the right spaces for you.

  5. LainaDiane

    Ahahahaha 85b gave me a 36A. Currently Im wearing a 34DD but thinking I might be a 32F. thats more than a little off.


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