Introduction: Find Your Bra Size

Picture of Find Your Bra Size

It's important to make sure that your bra fits well - an ill-fitting one isn't just uncomfortable, it can lead to back and shoulder pain, poor posture, and it tends to look bad as well.

Finding your bra size isn't hard - it just requires a measuring tape and a little simple math.

Note: There are (kind of goofy) illustrations of boobs in the following steps; if they offend you, I'm sorry in advance. If it offends you that they're just drawings (and not real boobs), sorry about that too.

Step 1: Measuring the Band Size

Picture of Measuring the Band Size

To determine the band size you need, measure around your chest just under your bust (just under the breasts). Make sure that the tape is against your body and straight across your back. Exhale as you take the measurement, but try not to pull the tape too tight (it should not dig into your skin at all).

Round all fractional measurements to the nearest whole number. If the number you get is even, add 4 inches; if it's odd, add 5 inches - jot that number down, it's your band size (the 34 portion of 34D, etc.)

When measuring, it may help to have someone else measure you to ensure that the tape is not twisted, and that it's parallel to the floor around the back.

Step 2: Measuring the Cup Size

Picture of Measuring the Cup Size

Place the measuring tape across the fullest portion of your bust, ensuring that it is parallel to the floor, and not digging in or gaping away from your body. If needed (depending on the size and shape of your breasts), this measurement can be taken while wearing a non-padded bra - just make sure that it is not too tight or binding.

Round all fractional measurements to the nearest whole number.

From this number, subtract the number for the band size - this will tell you your cup size (see chart in next step).

Step 3: Getting a Better Bra

Picture of Getting a Better Bra

This chart will help to determine what bra size you need.

A few things to remember:
1. The center portion of a bra should fit between the breasts and should sit against the skin, not gap outwards.
2. Straps should not dig into the shoulders or hurt. If they do, try loosening them slightly, or try adjusting the band of your bra to make it looser.
3. The back band of the bra should sit across your back below the shoulder blades. If it pulls upwards, try loosening the shoulder straps.
4. If your bra has underwire, they should not dig in to your body or feel uncomfortable or painful - this is a sign that the bra does not fit you well.
5. The fabric of the cup portion should not bunch up (it's too big) or not cover the breast (too small).
6. If you gain or lose a lot of weight, you should re-measure and consider getting new bras as ill-fitting ones are rather uncomfortable.


AnnaW81 (author)2016-10-09

This doesn't work for me either... According to this, I'm an A. But A cups are too small for me. In cheap bras, a B fits well; in an expensive bra, a C fits well.

SherylinRM (author)2016-07-15

Ok so I add 5 inches to get my band size.

Then deduct my breast size from that.

I get negative 1.

So I must be indented then lol.

This is nonsense sorry.

I have plenty of boobage and wear a comfortable C for years now.

victoriashklanko (author)2016-06-02

Measure loosely around the fullest part of your bust, with the tape straight across and around your back, bringing it to the front.

tineca7 (author)2013-08-07

I'm sorry my sweet, but adding inches only works for extremely bony women or obese women who slip them on, over their heads.

ballsackcream (author)tineca72015-04-21

jk ily

fuzzybunny2222 (author)2013-10-26


april420 (author)2013-02-27

this method was inaccurate for myself and i noticed it was for other readers ...but it got me thinking, every body is different so here's another measurement technique i some methods don't work for everyone so try a different one. :)

whoelsecanitbe (author)2012-05-27

Holy I have a Big bra size !!!! Im 13 and I have a DDD !!!!!! Never thought that > :(

ninjarabbit91 (author)2011-05-22

this doesnt make any sense to me. why add 4 or 5 inches? i did that and my bust is 40 and band is 39, that means im a b cup which i am not. they way i measure bra sizes is around the bust, 40 and around the band, 36ish, tht number difference is how i calculate not by adding numbers, the difference is about 4inches and that puts me at a d which i am. not a b.

I'm sorry that you don't find that this method works for you - personally I've not had a problem with it.

Tiktaky (author)2011-02-16

The shape of your breast plate is also a factor, flat breast plates can affect the over-bust measurements , while the cup sizes stay the same. To avoid this, Try and be very vigilant about keeping the measuring tape flush with your skin.

Ultimately, you only know what bra size you are when you try on a bra and it lines up and fits perfectly. But this is a great system to know which end of the clothing rack you should start looking.

tezcatbus (author)2011-02-13

The problem with this is that it doesn't actually work. The vast majority of women aren't wearing the right size bra, and the only way you're going to get the correct size by measuring the bust portion is if the bra you're wearing supports you properly without the underwire popping out from under the bust, poking out from the middle of your chest, or digging into your ribs on the side. If any of those are true, you're very likely wearing too large a band size and far, far too small a cup size. In other words, you can only find your exact bra size with a measuring tape if you're already wearing the right size!

Also, your bra sizes stop halfway up the scale - it's possible to buy bras off the rack that go to J cup. It has nothing to do with being fat, and everything to do with how much breast material is present.

According to the above measurements, which I always followed, I'm a 40DD, because DD was as high as my cup projection ever allowed, and I suffered through 20 or so years of discomfort and pain as a result. 5 years ago I was hired on at a lingerie shop, and I was immediately fitted by the owner as a 38I.

40DD and 38I are not near each other, but the former is what I got from a measuring tape, and the latter is what I got from an experienced fitter who didn't touch a tape. :D

I have since lost about 45lbs, and I am down to a 36H, which is another matter... women think they're losing cup size when they lose weight, when most of the sagging, bagging, and unhappiness comes from swimming around in a HUGE band size. Your band SHOULD be tight - it's where your support comes from. Bra straps are for shaping - if you have to tighten them to get lift, you need a tighter band and a larger cup, probably.

Anywho, just thought I would mention that. Sizes over F are really common - stopping at triple-D is like not showing women's shoe sizes over an 8.

Good luck and thank you for the info either way, its good to see people who want to inform others!! :)

shesparticular (author)tezcatbus2011-02-13

Thanks for your comments!

I'm afraid I'm not sure what you mean "doesn't work" or why you would need to be wearing the right size bra to fit yourself using a measuring tape. As noted here, you should measure while not wearing a bra (unless the shape of your breasts would make that difficult - in which case they could be supported with your hands while someone helps you measure, or with a bra that lifts them and is as well-fitted as possible). Step 3 here also provides some additional information about signs that a bra doesn't fit well (straps digging in, the center gaping away from the chest, etc.).

Regarding larger sizes, I am personally well aware of the scale for sizing going larger than indicated here (before I had surgery I was a 34FFF). I only made the chart/list go as far as DDD because I could not fit more information on it. I should have indicate that the "pattern" of sizing follows the same way - adding one inch to the difference between the measurements means adding a letter size.

As noted in the tips in step 3, gaining or losing weight is for sure a reason to re-measure yourself. That said, the band of your bra should be snug and it should fit against your skin well/comfortably, but should not be "tight" - it should not dig into the skin or feel like it is digging in. Also, it should not pull up across your back, if it does, the shoulder straps of the bra are likely too tight and the band may be too large.

Thanks again for all your comments!

Thank you from a guy Shesparticular. The next time my wife goes shopping for a new bra, at least I will know something that might help.

So glad it's helpful!

frollard (author)2009-03-17

The worst part about censorship is ****** *** *******.

Good Ible. I just did the math, and mine is a "AAAAA" by those standards. The measurements are the same. This of course is not surprising, as I'm male.

Maleman (author)frollard2011-02-13

Censored... I wonder what is so special about a woman's nipples that they must be censored, or it is indecent to breast feed in public....

That also reminds me of an old joke: How do you make 2 lbs of fat look beautiful? Put a nipple on it. :D

frollard (author)Maleman2011-02-13

hear hear!

shesparticular (author)frollard2009-03-18

. . .and now I'm dying to know what it would say. Thanks - I guess I should have mentioned it's not exactly an 'ible for the fellas, but I guess it's a good thing to know how to do just the same.

frollard (author)shesparticular2009-03-18

I was SORELY SORELY tempted to post pictures...but I can't find my camera. Literally, its gone. I'm quite shaken.

WKD_Side (author)frollard2010-01-14

dude i thought of doing exactly the same thing! now wheres a tape measure when you need one! 

frollard (author)WKD_Side2010-01-17

Seemed like a good idea at the time :S

JohnJY (author)2010-07-06

36-24-36? Ha ha, only if she's 5'3".

MrHanimi (author)JohnJY2011-02-13

aaah sir mixalot you lyrical womanising rapper.

tbcross (author)2010-08-12

I have a terrible time finding the right size I am now wearing 34DD and the band is too loose, and your right most women don't know. We just try em on till one is moderately less uncomfortable than the rest!! Thanks great ible!!

CoffeeWoman (author)2009-04-03

This is an awesome 'ible! I do costuming and other sewing and have noticed two universal "truths": 1) 99% of teenaged girls think their 'waistline' is a hair-breadth above their hipbones and 2) regardless of age, most women do NOT know their own true bra size. Don't go shopping without figuring out your real size!

Thanks! I realized when I had surgery that I really never had known what size I was. I think it's really important for women to know how to measure themselves, as well as to know their real size (or at least what it should be, since bra sizing tends to vary so much).

I was basically flat chested until the second half of my Junior year of high school. Then I grew from an AA to a full B in the space of less than two months (I gained 10 lbs in that time...115 to 125 lbs). Now I am in my second year of college and I have been wearing a 34C for the past couple years. I recently gained some weight (I'm 5'5.5" and about 140 lbs) most likely due to my hypothyroidism. As a consequence of this weight gain, my chest got larger. I knew that I had been wearing the wrong size for quite a few months, but I usually don't like shopping unless I really need to. Well, I went to Victoria's Secret two days ago and got measured. She said I was actually a 36D. I tried on a few VS bras and they fit wonderfully. I didn't feel like paying $42 for one bra, so I went to a different store. I found some bras by New York Elegance, but the 36D didn't fit! The band was too large and the cup too small. So, I wound up buying 6 34DD's and one strapless 34D and they fit quite well. :)

If they don't know how to measure themselves, I now feel confident in my abilities to assist them after reading this instructable. ;-) So if they have issues send them to me, and I can help them out.

Ninzerbean (author)2009-07-27

I am wondering if you mean to subtract the 1st number from the 2nd BEFORE you add 4 or 5 inches?

I'm not sure how that would make much of a difference in the final number that you'd get, but no, I've always been told to add 4 or 5 inches (depending on it the number is even or odd) and then subtract to get the cup size.

mollyb (author)2009-03-26

Personally I don't understand the need for this Ible but thanks for sticking with the drawings. They work just as well as photos and keep it from becoming, "one more thing to keep my kids from looking at."

shesparticular (author)mollyb2009-03-27

I first wrote it to enter it in the Burning Questions contest, but I think it may help women or girls who don't know the importance of a properly fitted bra. Thanks for the comment - I also think the illustrations serve their purpose just as well as photos would, and may also be more helpful here.

KreaKatri (author)2009-03-24

This is clear and easy to understand. However, last time I was shopping for bras those who worked in the store refused to measure me, because their experience was that it was not precise, and would give you the wrong size. If they are right you can't really use this method.

shesparticular (author)KreaKatri2009-03-24

Thanks so much for your comment. In my experience, the people working in the store who would refuse to measure women just didn't want to, and would say things like that to avoid it. That might not always be the case, but I personally preferred to measure before going to the store and then always to also try on bras before buy them.

KreaKatri (author)shesparticular2009-03-24

They seemed to mean, but you never know. I do think measuring will give you a good idea about your size, but as you say, sizes vary and you should always try them on :)

NachoMahma (author)2009-03-12

. Nice iBle. . Kind of hard to show how to fit a bra without some kind of depiction of breasts. I think you handled it very well.

Thanks, I just would rather not post mine, so it seemed like the only option.

. There have been a few members that have posted pics that showed a little bit of breast (LED pasties and molds for chocolate breasts are two off the top of my head). The response from the younger males (and a few of the older ones) was rather humorous.

I'm still considering adding some, but I don't think it's really needed for clarity of the explanation (if you think I'm wrong, please let me know). . .and I'm also not really in the mood for explaining that they're my boobs, and I didn't have to "get someone to let me take pictures of her boobs" as I think most of the other ladies have.

. The drawings do a very good job. Since you already have the iBle put together and published, I don't think it would be worth the effort. YMMV. . But I'm all for pics of breasts. Maybe for your next iBle. heehee

frollard (author)NachoMahma2009-03-18

I second that. As a nearly-married mostly-responsible person. Pictures make life better.

You could also likely do the photos using a store Mannequin if you explain your project to them, but I do like the drawings you came up with. As well your smile.

I hadn't thought of that - I guess it could have worked as well; thanks.

EPL (author)NachoMahma2009-03-12

yes but also perverted. for example in body casting and chocolate molding the author was holding petroleum jelly in front of the breast and one comment was.... "you have some nice......... petroleum jelly." you can find this in featured offbeat.

rickyd! (author)EPL2009-03-16

omg lol

garrettmikesmith (author)EPL2009-03-15


Phil B (author)2009-03-12

This is an informative and easy to follow Instructable. I am a male, so I can not make a lot of use of this Instructable. But, it makes me wonder. I remember hearing a few times that most women do not have a properly fitted brazziere and have some of the various problems you mentioned. You make it sound easy to get properly fitted. Why are most women not properly fitted?

shesparticular (author)Phil B2009-03-12

Thanks very much! I think a lot of women (myself included sometimes) assume that they know what size they wear (especially for bras) and assume that that doesn't change - and even from one brand to another can make a huge difference in the size (really is unfortunate, since it makes it even harder for women like myself with larger breasts to find bras that fit well). Also, it's much much easier to have someone else measure you, or at least help, and I think that might be embarrassing for some women.

Phil B (author)shesparticular2009-03-12

My wife sews most of her own clothing and does many alterations for some other women. She constantly impresses upon me that garment sizes can vary greatly from one manufacturer to another. She reminded me of that when I went to buy a zippered nylon cover for a new Bible. One maker's large size would not fit, so I looked for an extra large, but could not find one in the style I wanted. I finally bought a large by a different maker and it fits perfectly. I suppose there is some vanity involved, too. By analogy, in my mind I still have the 34 inch waist I had in high school. In reality, it has been decades since I wore a pant with a 34 inch waist. In a few days I will be 63 years old. Life is full of little indignities that one by one remove reasons to be proud enough to become embarrassed. Once I had surgery and was nauseous a couple of days later. I vomited all over myself and the bed while a couple of nurses I had just met were talking to me. A few seconds later I was running naked for the shower. All three of us were forced to treat it as a normal occurrence.

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Bio: Learn more about me here: or follow me on Twitter (@shesparticular) (if you're into that sort of thing).
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