Survey results // 1000+ women surveyed for size chart infographic // Closet Case Files


Infographic of sizing survey of 1000 women // Closet Case Files

You may remember that I did a quick sizing survey a few weeks ago. I had a few questions about my sizing model and wanted to make sure it worked going forward. Over a thousand of you filled it out (THANK YOU SEWING ANGELS!) and I had a number of requests to share the results. In my silly, naive fashion I thought, “Oh, I’ll just throw some numbers together and make a quick infographic!”

There is no such thing as a simple infographic. After importing all the data and figuring out how to collate everything in Excel, I then spent an inordinate amount of time trying to visually render the information I captured. While it ended up taking wayyyyyyy more time than I expected, it was a worthwhile exercise since it  actually forced me to engage with the data in an in-depth way. I chose a few key things to share with you today; I think the results are pretty interesting.

When I developed my sizing chart, I was working from pretty “standard” measurements from the ASTM, which in turn were captured from massive polling and studies of women’s bodies (you can purchase the data I based my chart off of here). It was somewhat reassuring to discover that my size 10, which I use as a sample size when drafting, is more or less the average body size of the women I surveyed. In the graph of bust, waist and hip measurements, the peaks represent my sample size 10 measurements almost exactly, in addition to working out when all the numbers are averaged together.

To be honest, I was a little surprised by this since I have often heard that the average dress size for American women is 14. I’m not sure if my data pool is not quite broad enough, or if a size 14 in those studies is a little abstract since there is no real sizing standard in the fashion industry. In my own chart, I’m a size 10 at the  bust, 12 at the waist and 14 at the hip. Unfortunately I couldn’t figure out a way to figure out how typical this size straddling is since Excel makes me want to cry just about every time I use it. Needless to say, I think the averages that I came up with in this survey should be taken with a grain of salt since it was hardly a proper, statistical analysis; I think a more well-rounded view would be obtained by polling readers of lots of blogs. I’d be highly curious to see how my results would change if I had also surveyed the readers of the Curvy Sewing Collective, for example.

In terms of bra sizing, while C cups took the slight lead in terms of overall population, 34B was the most worn bra size at just under 10%. However, after comparing many ladies actual measurements and noted bra size, I couldn’t help but concur that quite a few of you are probably wearing the wrong size, even when taking into account all the different bra sizing schools of thought. One thing I noticed was that the larger the bust, the more accurate the sizing seemed to be. I can only guess that very large busted women are more likely to get properly fitted for bras because it’s imperative to support the ladies. If you’re unsure about your own size, I highly recommend going to an independent lingerie shop or a good department store (no no no Victoria’s Secret) and get a professional’s advice; you might be surprised by the results!

Finally, I promised two patterns to a random person from the survey; I randomly scrolled and stopped at the first name my mouse clicked.  I’ll be emailing @sbothma today to ask her for her choice.

Thank you so very, very much for your time and help with this survey; I feel like I have a much more nuanced understanding of your shapes and fitting issues now and it will greatly inform and improve my work going forward. Hopefully you find some of this data as interesting as I do!

  • Caitlyn Myers

    For a really great fitting resource at home, check out It’s maintained by Reddit user irisflame of the super helpful and lovely subreddit /r/ABraThatFits. Both sites are chock full of useful information, and the members of the subreddit happily provide measurement checks, fit analysis, product reviews, tips on where to shop, and all-around awesome support for anyone who wears a bra or wants to.

    • THIS IS AN AMAZING RESOURCE! Who knew reddit wasn’t just filled with angry dude teenagers??!

  • So interesting! I agree that it’s surprising the Size 10 came out as average… I wonder if blog readers are self-selecting to read blogs by designers who design for their size range? If you ever want to pick the Curvy Sewing Collective’s collective brain, just give us a shout! 😉 Your inforgraphics and bee-yu-tiful!

    • Christina Mano

      I definitely don’t self-select reading blogs by designers that design for my size…but get sometimes fed up having to grade patterns up ???? so I might boycott buying patterns that have a ridiculous size range….

      • I get confused sometime seeing really narrow size ranges. You can grade up and down quite alot before you need to draft a second block….

      • I have to admit, I protest companies that size me out of their range by not reading their blogs. Come on, people, at least make it go up to my bust size, even if I have to add a little for the hips!

    • You need to run the survey! I can show you how to organize the data so it’s easiest to collate and import 😉

    • Honest Amanda

      I don’t self select, either. However, when I find body doubles I read them religiously because anything they make I can get a good idea of what it will really look like on me. Also, I think I could make a FBA in my sleep based on how many I’ve seen/read on various blogs…but as a 34A I highly doubt I’ll ever need this skill;-)

  • Love this infographic! Unrelated, but this just popped up & I thought of you immediately:
    Check out those top stitching thread color names!

    • Amazing link Jess! Thank you! Gonna have to share in the weekly round-up….

  • Shape, not just measurements, matter for bra size. For me, no matter what measuring system I use, it puts me in the wrong bra size. I did get professionally fitted once for a bra that was 3 cup sizes larger that my measurements say I should wear. The cups were the right volume, but I couldn’t wear it because the wires were too narrow and the bridge was too wide. So measurements only work to determine bra size for women with average shaped breasts, something it took me years to realize.

    • This is very true. Bra sizing can be a bit complicated but I think sometimes just trying on a million sizes until you find one that works is the way to go 😉 My observation based on teh survey was that a lot of people were probably wearing the right cup size in terms of volume, but had bands that were not tight enough, especially with larger breasts…. So many people wearing a 36C for example, would probably be better off in a 34D.

  • I was hoping you would share this! I’m surprised how close I am to the average size of Closet Case readers. I always feel like altering a pattern at all means I’ve got a freakishly distorted shape. 🙂 I wonder how common it is to have the measurement of a straight size.

    Beautifully descriptive graphics!

    • No freakishly distorted shape! I have to sew between three sizes on my own patterns!!!!

  • Karen

    I find your results quite surprising as I’ve sewn for hundreds of women over the last 40 years and the average size of my customer is definitely larger. Interesting…

    • I think it may be an good old fashioned case of sample bias….

  • I’m pretty sure that the sizing thing is a case of sample bias: people who fit in your pattern sizing are disproportionately likely to read your blog and answer a survey (and, perhaps, women who are bigger are more reluctant to share their measurements).

    Which doesn’t mean the results aren’t interesting! But means that they’re probably not representative of the community as a whole. Same would go for my readers – they’d probably be more plus size than the community, on average.

    On the bra size, I think the average/median/mode makes the results confusing – you can see from the pie chart that the median is much more around the D size.

    • Christina Mano

      I totally agree Jenny ???? I realized when reading the results from the survey that apparently I’m not a typical Heather customer…you’re also right that curvier women might be less likely to share their measurements. I do it all the time (48-40-50) as I would like more patterns to have a wider size scope…which is also why I often volunteer to test patterns even when that means I have to grade them up. Thanksfully there are more options today. I am by the way super grateful for Cashmerette patterns ???? and for The curvy sewing collective????

    • Sample bias! That was the expression Iw as looking for when I was writing this.

      You should do a similar survey on the CSC and we can compare 😉

  • K_Line

    Awesome post and thank you for suggesting that there is evidence that many women wearing sub optimal bra-sizes. I see this all the time (I’m one of those people who does know her size and I’m in the small back / large cup bracket.) Sometimes, when you sew, you can get away with making the “wrong size” because circumference of fabric can be eased around the entire body – so a small back/large bust shape can pick up some of the bust size with back size. It doesn’t tend to produce optimal fit, but it can work. Also, breast shape (projected vs. shallow can make a huge difference on this account). All I need to do is look around me at work (or at blog photos) to see that women are generally overestimating band size and underestimating cup size, sometimes extremely. I do wish that peeps could get with the understanding that a UK 30 G (for example) means a 30″ underbust measurement and a 39″ full bust measurement. A woman of those dimensions, who puts herself into a 36DD (same cup volume), is going to get no support and, if her breasts are projected, will likely still fall out of the bottom of the cups or experience top cup pillowing. It’s unnecessary. There are lots of bra sizes to be found now and the offerings are terrific.

    • Apparently the +4″ or +5″ band mentality is bad for women with large breasts for exactly the reason you’re saying! You need more support in that band. However, I’ve had conversations with a few bra designers about this and the consensus seems to be that women will often go for a larger band/smaller cup because those big cup numbers are scary…

      • And I will just throw in: Heather, if you are ever in Toronto and want to go bra shopping with a true master, get Kristin (K_line) to take you too the store! She ‘s the one who got me out of a 36DD!!! (Ack! 36G now.)

        • K_Line

          Thanks for the plug G! I welcome the opp to go bra shopping with either, or both, of you any time!

          • I would love to meet!! You’re one of my favourite commenters 😉

      • Gwenhwyfar

        Not to mention that once you fall out of the C cup, there are few fun or cute options to be had in RTW, even fewer once you surpass D or DD.

  • Wow! I’m almost perfectly average (just an inch shorter) – that’s interesting!

    • Tiffany, you are not average, you’re a unique snowflake! (haha)

    • I should also add that I used to think I was a 34B but since making my own bras I’ve found that I’m actually 38B – a size usually can’t find in store.

    • Honest Amanda

      Me too! Although I don’t wear a 34B either.

  • Christina Mano

    I was also surprised by the measurement of the “average” woman you got from your survey. I’m outside your size range but still choose to grade up/sew your patterns. I like your blog and your patterns because they’re young, sexy and fun…which isn’t necessarily common in curvy patterns. But apparently I’m not your typical follower/customer (or other curvies are reluctant to share their measurements?). I also read/follow the curvy sewing community, including Jenny from Cashmerette (love her patterns????) and Gillian who obviously both follow you.

    • I’m really not sure this survey is totally representative of my base, especially since i have a slightly wider size range than teh average indie and have lots of curvy customers. Jenny made a good point about maybe curvy woman being less likely to share measurements? Who knows!

  • I’m one of the 34Bs wearing the “wrong” size, and after years of trying to figure out what I’m doing wrong, and what my “true” size is, I have come to the conclusion that those charts just don’t work for everyone. My upper bust is 33″, full bust 33″, and under bust 27.5″. According to the standard magazine calculations in those articles that tell you you’re probably wearing the wrong size, you round up the under bust to the nearest whole number and add 5″ to get your band size (33″), then subtract that from the full bust to get cup size (0″?), but the smallest on the chart was always at least greater than 0″ for a AA. I know I don’t have much, but I’m not completely flat! So then those new measurements came out that say you don’t add the 5″, which put me at a 28E (also laughable!). And then there’s the sewing pattern method that has you subtract your upper bust from full bust to get cup size (back to 0 again, not even an A!). At this point, I decided to go to the store and just start trying on all the bras. Bands smaller than 32 felt like corsets, and bigger than 34 were shifting all over the place. A cups caused all kinds of bulging, and larger cups had extra room. So ended up exactly where I started at 34B! And the wires were still poking me, so I’ve given up and I wear camisoles now. Life is too short to be uncomfortable.
    *End of rant*.

    I just wanted to provide a real example of when size charts just don’t work. I spent years thinking there was something wrong with me for not fitting them. Thank you for spending so much time compiling the data into pretty charts – I love that stuff!

    • Hahahaha that sounds so frustrating! I think for a lot of women teh only way to find their real bra size is to do just what you did and try a bunch of stuff on. I’m glad you had it figured out. Based on your measurments I would have probably suggested a 32C which is the exact same cup as a 34B, just on a wider band. I think it really comes down to what you find comfortable. One thing I’ve read is that women with bigger busts (over a D, say) benefit greatly from a tighter band, while women with smaller busts and smaller ribcages don’t require as much support and may find a tight fitting band too small. Then you add in the whole “no consistant sizing between brands thing and it can get really confusing!

      • It’s gotta help that larger ladies have more fluffy padding for a tight band to sit against! I wear a tight band, myself, ’cause nothing else will hold the ladies in place… but I can imagine that if I didn’t have that padding under my sine, a tight band would be unbearable!

    • Interesting – I only have a 1″ difference between my upper bust and full bust (an A cup I believe), with a 5″ difference between my bust and underbust. My favorite bra is a wireless 32C from Gap Body. Following the Watson Bra measurement instructions I came out as a 30C. I made that size and it was sooo tight it was unwearable, so I made a 32B with a slight cup adjustment that I think made the cup slightly bigger. So I still have no clue what my “real” bra size is…

    • Pam

      Honestly I think the new sizing approach just doesn’t work for small boobs. I’m a 30 full bust, 28.5 upper bust, 27 under bust, and it suggested a 26D! I really have pretty much nothing there, definitely not a D cup in any bra. I wear a 30AA or sometimes a 30A depending on the cut and that size is extremely comfortable.

    • Jennifer R

      Been through the same. When nothing else in clothing has accurate sizing, why do we trust bra manufacturers and assume it’s women who are wrong? I’ve tried them on and know what I’m after. I also will alter a bra that’s starting to stretch out, by taking a tuck in the bands or cutting down the straps as needed and re-attaching to the slider, does a world of good. I’d be highly skeptical that women who sew are wearing the wrong size bra en masse.

      • From what I hear when I talk to bra designers, it’s the case for a lot of people! A lot of women should be in bigger cups and smaller bands but get scared by hearing “DDD” cup.

        • Jennifer R

          That certainly is what one hears but I suspect it comes more from people crunching spreadsheets, like you were doing, than actually sending women home satisfied in a new bra size. I’m a 34C sometimes 36B (a 32 D or 30 DD also have the same cup but they would be painful or just impossible to fasten). Before anyone ever explained the curiosity of labeling the same underwire differently depending on band size, I had discovered the near equivalence 34C & 36B in the fitting room. I’d suspect most women make similar discoveries unassisted, experimentation is usually more powerful than analysis for an individual. There’s just more to bra fitting than measurements and I’d agree with others that this is more apparent in smaller sizes. Something I read regarding menswear warned that chest measurements need to be taken at the most prominent point of the shoulder blade. Obviously this doesn’t apply to womenswear but it did remind me that there are many factors contributing to any circumference taken and it’s hard to glean the whole story from measurements. I mean would your data indicate, prominent shoulder blades, or to be ridiculous, breasts on the wrong side of their body? If not, I don’t think it can predict bra size with much reliability.

          • I totally agree! I have broad shoulders and prominent shoulder blades which I’m sure contribute to the fact that my upper bust and full bust measurements are the same. I think those charts are designed for average sizes and shapes, and the system breaks down for anyone who’s too far away from average. I definitely trust my own experience over a spreadsheet based on averages, especially when it suggests something that’s physically impossible to fit into!

    • Kathryn

      Just curious, habe you ever actually tried on a 28E bra? It might not actually be laughable. The letters in a bra size are all relative-they refer to the cu size relative to the band size. An E-cup on a 28 band is not exactly adult-film-star huge, though that is exactly what one would imagine when hearing that number.

      I wore 34C for well over a decade, which fit alright but not great. When I went to the local boutique and got fitted, lo and behold my size is actually 28G or 28F, depending on the manufscturer. It hurt my ego for a moment to hear that for sure. It sounds ridiculously huge, but actually the cup size is almost exactly the same as on a 34C. It’s the band size and cup placement that work so, so much better for me now. Maybe look into the 28E, it might be exactly what you need!

      • The 30 band felt like a corset, so I doubt I’d even be able to get a 28 closed! Unless a 28 means something different at a boutique bra store, which wouldn’t surprise me, but then is there really a difference between a 28 boutique and a 34 mall band if they are equivalent? I could see the cup placement being different, but that would be different for each person since the same size doesn’t necessarily mean the same shape. So many questions! Anyway, I’m quite happy just wearing camisoles instead. It’s been two years, and I can’t imagine any bra being more comfortable than none at all! 🙂

        • Honest Amanda

          Yes, I’d say enjoy your bra-free living! I did, until I was pregnant, and in the subsequent years after kids. I require a little more modesty now (for comfort/confidence) as well as support if I’ll actually be walking about or going up/down stairs.

        • Kathryn

          Well, bra-free is by far more comfirtable, can’t argue that! I am gradually increasing the occasions that I dress without a bra. I’m on the larger end of things, bust-wise, so it’s going to take more confidence-bulding to really get there, but I aim to someday. It truly does feel miles better!

    • Honest Amanda

      I’m similarly sized/shaped to you. I’ve found that some brands simply do not make anything that will fit me (Victoria Secret for instance). Others like Calivin Klein and DKNY are hit and miss…a 34A will sometimes fit perfect, but if not, chances are going up a size won’t work. I’ve settled on GAP wireless bras. I say “settled” because they are imperfect, the upper part of the cup is less than full on me. But, there are no bulges, they’re comfortable and they stay put. Because of the substantial lining to the cup you can’t tell that there is excess space anywhere, nothing gapes or wrinkles.

      • Those are exactly the same ones I settled on too! I keep one in my drawer for those rare occasions when wearing a bra is necessary. 🙂

  • TracyLou

    This is interesting. I always considered myself to have a big booty – but according to your results, my booty is average, my waist a little larger, and my bust a lot larger. hmmm. I”m also shorter than average, but then, I knew that 😉 Thanks for sharing your findings

    • Averages are boring, real bodies are beautiful 😉

  • Monserratt Lopez

    I love data analysis!!! ♡
    This is fascinating! !!! Thanks for sharing darling! 😉

  • Jo

    Thanks for sharing the findings – interesting stuff. It would be really useful to know the sample population (ie number of respondents) for this. The sample size is a very important factor, and should be reported along with the averages – that way, people know whether 10% of respondents equates to 45 or 450 people.

    • Hi Jo. The final tally was over 1000!

      • Jo

        Thanks for that – and great that you got such a good response! I’m only sorry I forgot to fill out the survey.

  • Well, it’s official. I am freakishly proportioned! ha ha ha This is so fascinating, although I’m sure it doesn’t reflect the demographic at large as much as the demographic that is attracted to your patterns. I would be curious to know how many women do straddle more than one size – and how many wear different top and bottom RTW sizes. I always wonder who these ladies are who wear the same top and bottom size.

    • angelac

      LOL, me too! I feel like a Seuss character – which translated means I need to get serious about losing some adipose tissue around my waist.. ahem…..

  • Kristine Mackin

    I was thinking about a way to easily determine how many people cross sizes, so I took a look at your size chart. It looks like the bust-waist difference is a standard 7 inches across all sizes, and the waist hip difference is 11? For each individual respondent, you could subtract their bust from their waist, then their waist from their hip. If the difference is more than, say +/- 1 inch from the standard, they likely qualify as crossing sizes. That subtraction should be easy to apply, depending on how you’ve formatted the data. If you need to visualize it more easily, you could then either apply conditional formatting to identify outliers, or further transform the data by subtracting 7 or 11 from the result to see how far outside the size grading an individual is.

    I hope that works, and makes sense!

    • This is awesome! Clearly someone is an Excel Yoda 😉

  • Genevieve

    Okay, to start I was seriously BUMMED out when I saw your info graphic! It appears I am not as unique as my husband tells me everyday ????. He tells me I have “smothering” breasts…hehehehe. I guess that there are many, many other women who have smothering breasts too….booh! Seriously though, this information is terrific and very interesting. I guess that the hour glass figure is really not the most common shape of a woman, unless you are from Barbie’s DNA 😉
    Thanks Heather,

    • I think on average we’re more pear shaped. Tasia at Sewaholic was probably onto something!

  • Charlotte Elliott

    Interesting! I always thought I had small breasts (being a 34B) but according to your survey I am smack, bang average. At 5′ 5.5″ (yes I always count the extra .5″) I am pretty spot on for height too.

    • I draft for a height of 5′-6″ so at least I’m not far off myself 😉

  • I hate that many soft bras are sold with regular clothing size (letters or numbers). I mean, S is too small and with M I have nothing to fill the cups.

    Breast size is an odd thing. After I had lost almost 15kg, my boobs went too, naturally. And it didn’t bother me the least. Until one fine day, a lady on the bus called me ‘young man’. Sure, I had a pixie cut and was wearing pants… an honest mistake to make. But, it turns out even in your late 20s a strangers comment can hurt ones self esteem. I started to wear push-up bras, the kind that really make your boobs 2 cup sizes bigger. Silly. Now, it might be that I have longer hair again, I don’t really care how my boobs look to other people.

    • I used to wear push up bras all the time but in the last 5 years or so I’m much mor eintoa natural boob shape, ie #thisiswhatmyboobslooklike. Wearing something with tons of padding and gels and whatnot feels as foreign now as padding my hips!

      • I like light padding the best. That thin layer of foam I don’t mind.
        Speaking of, do you think one could use super thin neoprene instead of underwear cup foam?

        • I don’t see why not! It has a bit more stretch than bra foam but I think would make a great bra. *starts eyeing pile of neoprene in stash cabinet*

  • Mel

    I’m pretty close to the average. What I found interesting is the waist size. I’ve always been quite self conscious of my waist size (as it wasn’t in the 20’s) but hey its how I’m built. Nice to also see that I’m not the only one struggling with pants (legs are always loose and waist too small).

    • Pants are impossible to buy if you don’t have the exact proportions they were sewn for! I have lots of customers with similar waist/hip measurements and its IMPOSSIBLE to find stuff that fits without an elastic waist…

      More reasons to sew your own!

      • Lorna

        Yes! Me too. My hips are 40″ – but my waist is 39.5″! Buying just about anything is a nightmare, so I hide in stretchy jeans and big cardi’s. Too scared to venture into sewing pants, but I’m sooo tempted by the thought of my own Gingers. One day!

  • different shops measure bras differently. some time ago, I just measured my band size and went cup size I was most comfortable with which is 32C (previously I had been measured at 34B and 36C at one point)

    • Well technically a 34B has the same cup size as a 32C, its just a looser band 😉

  • missceliespants

    I cannot recommend going to a specialty bra shop enough. I was wearing a 36D or 34DD for YEARS until I went to not Victoria’s Secret and found out I was two band sizes smaller and several cup sizes larger. VS tries to sell you on ‘sister sizes’ and padding. Once I got into the right bra, my clothes fit better, I looked better and haven’t looked back.

  • Susan Buchanan

    Basically everyone needs to go down in band size and up in cup size! I worked in retail at a bra store before going into tech design, and even I didn’t notice when I needed to go up in cup size because I had been so brainwashed into thinking I have small breasts that C just didn’t seem realistic. Then I tried it on and it was life changing!

  • Yeah but you are well known as an awesome designer for pear shaped women so you probably have a disproportionate number of pear shaped lady followers, which would seriously skew your results. I would wager that the survey wasn’t a good tool for the elusive “average” woman. I mean, I am not a pear shape and I still love your blog, so I’m not saying we rectangles and apples didn’t fill the survey too, just that it’s some “fruit” for thought 😉

  • Alipally

    overall measurements are definitely one discussion, but from reading the comments here the question of bra size is a much more interesting topic of conversation.
    As someone who is currently undergoing a serious diet (I only get this frame of mind every decade so I’m taking full advantage!) I’ve recently lost 32lb and am planning on losing quite a bit more……. my bra size has gone from a 40E down to a 38E. My breasts have definitely shrunk and I could have just gone to a 40DD and the cup size would still be OK, but the bra would have ridden up my back!
    Bra sizing is also quite subjective. I wear a mid priced brand (Berlei) and found their sizing to be consistent across their ranges….. other brands don’t seem to fit as well, no matter which size I try.

    My advice is find a brand that fits your bust/under bust and stick with that brand. Unfortunately this may cost you more. but ultimately comfort and fit take priority over cost. (for me at least) If Victoria’s Secret suited my needs that’s where I’d stay, but the pretty lace scraps are not even going to begin to cover me!

  • redletteryear

    These results are very interesting to me, because I had always read that sewing patterns were traditionally drafted for a B cup size but that most women average a C cup size, so it would seem that most women would be stuck doing a FBA on every garment. It would be interesting to see how these stats mesh with ready-to-wear garments sizing as well (although those of course vary over time/brands, but I’m sure there is a standard starting point). It’s always been frustrating to me sewing, because although I can buy ready-to-wear in my standard size that fit well, I always have to do a FBA to get garments to fit while sewing.

  • Thank you for sharing! This is so interesting to read. My body has changed so much over the years and I think I might need a new bra size again.

  • This is very interesting – thanks for sharing the results.

  • Hi Heather! I’m working on designing my first clothing line, and I remembered this super helpful blog post you shared awhile back (thank you!!). As I work on figuring out sizing and fit, I was wondering if you could share a bit about how you work on a size range that doesn’t exactly correspond to your body? I’m assuming you begin with a sloper that matches one of your standard sizes, not your own measurements. If so, how do you get the drafting and fit nailed down before you grade to other sizes if you’re unable to try it on? Or do you draft for yourself and then proportionally grade to a standard size from there? I’m used to drafting and fitting just for myself, and this is proving to be one of the most stressful parts for me. I would appreciate it so much if you can offer any insight into your process! Thanks so much! 😀

    • Hi Caitlin. I use a slightly modified version of the ASTM measurements for my sample size and grading system. It’s the most current, up to date study of “average” measurements for each size. My dress form uses ASTM standards as well so I have a consistent, accurate form for fitting. I don’t fit on myself since I fall between three sizes, although I’ve recently started using a fit model with similar measurements. Hope that helps!