You’re Wearing the Wrong Bra Size

April 14, 2014

blue bra

Forget everything you think you know about bra size. Pretty much everything the lingerie industry tells you is wrong (measure the circumference, add 4, subtract what…?). I’m going to let you in on Victoria’s biggest secret – they want you buy their stuff, so they will tell you that you’re a bra size (surprise!) that they carry in their store. Those big fat liars. This is post is going to be really long (sorry) but chock-full of important information! I wanted to include it all in one post for easy reference. A properly fitting bra is not a luxury – it’s a necessity.

  1. Start by wearing a somewhat loosely-fitting cami with a built-in bra. This will give you the most accurate measurements. Wrap the fabric measuring tape around your ribcage directly underneath your bust. You must 1) make sure the measuring tape is parallel to the floor all the way around your back and 2) exhale (to get the most compressed measurement) and pull the tape as tightly as you comfortably can without it digging in or hurting. 90% of the breast support comes from your band (not the straps!), so you want it to be tight. Write this number down as it is your new band size. If the measurement was a fraction, round to the nearest inch.
  2. Bend at the waist and let your bust hang (we’re letting gravity help you out on this one). Wrap the tape around your bust at the fullest part, again making sure that the tape is parallel to the floor all the way around the back. The tape should just touch you and not be pulled tight. Write this number down.
  3. Take the first measurement (band size) and subtract from the second measurement. The difference you get is your cup size. 1 inch = 1 cup size.
  • 0-1/2 inch = AA cup
  • 1 inch = A cup
  • 2 inches = B cup
  • 3 inches = C cup
  • 4 inches = D cup
  • 5 inches = DD cup
  • 6 inches = DDD/E cup
  • 7 inches = F cup

And so on. Be aware that this new measurement may contradict everything you think you knew about breast size. You may have been wearing a 34C (thanks, VS) but this new measurement is telling you that you’re a 30F. How could you possibly be an F cup?! No, you did not become Pamela Anderson overnight – you haven’t been let in on a crucial piece of information. Band size and cup size are an inversely proportional ratio. For example, a woman who wears a 30F and a woman who wears a 38F do not have the same sized breasts. The volume of breast tissue that a 38F bra holds is much larger than the volume that a 30F bra holds. A 30F cup is a fraction of the size of a 38F cup. This is a difficult concept to explain, so maybe this diagram will help:

bra size

Notice that the cup volume remains the same across each band size.

Now, what are you supposed to look for in a properly-fitting bra? It can get confusing, so here are some examples of wrong versus right bra fits:


The center gore should lie completely flat tightly against your sternum. Your breasts should neither be flattened nor spilling over the cups.


The underwire shouldn’t dig into your sides but should fully encapsulate all of your breast tissue.


The band should lie parallel to the floor and not ride up. The straps should not dig in or slide off.

images via

Once you’re in the changing room with your new bras, you should always use the “swoop-and-scoop” method to make sure they fit properly. Check out that link for some jaw-dropping before-and-after pictures of this method. Seriously. All that “armpit fat” and “back fat” that you think you have is actually migrated breast tissue. After using this method for a while, you may find your breasts slightly bigger due to the misplaced breast tissue migrating back to your breasts.

Keep in mind that the underwire of your new bra will extend much farther into the underarm than you’re most likely accustomed to. Don’t worry, this is actually the proper fit. Remember, all that “armpit fat” is really just breast tissue (and your bra should fully encompass the entire breast tissue). Each breast should individually be lifted and separated in its own cup with no line of cleavage! Shocking but true.

Also, remember that every woman’s breasts are shaped differently. Most likely you’ll either fall into the “full on top” or “full on bottom” category. To determine which breast shape you have, bend at the waist and let your bust hang freely. You’ll either notice that your breasts fill out from the bottom (“full on bottom”) or the top (“full on top”). “Full on bottom” breasts look best in full coverage bras, bras with elasticity along the upper edge of the cup, and push-up bras to mimic upper-breast fullness. If you have “full on bottom” breasts, stay away from demi or balconette bras, as the top of the cup will be loose and may look too big. “Full on top” breasts look great in a variety of different styles and it is much easier to find bras to fit this type of breast shape.

Even the best bras lose their elasticity after a year or so. When buying a bra, the band must feel tight on the first row of hooks. When the bra starts to lose elasticity, start using the second or third set of hooks to ensure that you still have a tight-fitting band. Always hand wash and air dry your bras to ensure their longevity and to retain their shape. Throwing your bra in the dryer degrades the elastic and warps the cups.

It is important to measure yourself about once a year to note any changes. If you’ve recently (in the last 6 months) lost weight, gained weight, had a baby, or are going through other hormonal changes, measure yourself again to ensure a proper fit.


Resources for bras:

Thirdlove: A SF-based lingerie company specializing in half-sizes to ensure a perfect fitting bra.

True & Co.: No more fitting room drama. Try on 5 bras in the comfort of your home for free! I just ordered mine and I’m giving you $15 to put towards your next purchase!

Curvy Kate: An online lingerie retailer that specializes in cute bras for busty women! Cup sizes range from DD to K and band sizes from 28-44.

Freya: Another great retailer for larger-chested women. Their bras are beautiful and well-made (and worth every penny!). Sizes range from 28D-K.

HerRoom: A really informative resource that goes in-depth into many of the things I mentioned in this post.