Hello, Sewcialist friends! Welcome to part 2 of the Great Shoulder Digest! This article is going to break down horizontal shoulder measurements, how to take them on yourself and on patterns for set-in sleeves, and most importantly, how to use them. Now that you know all about shoulder slopes, this knowledge should provide an accompaniment and make understanding shoulders even easier.
First up: let’s talk about your total shoulder width. This measurement is called “Across Shoulder Width”, and is taken from “bone to bone”. The bone in question is the outer point of the acromion, which is the uppermost and outermost point of the scapula (shoulder blade) that sits atop the humerus, or your upper arm bone.
Image is animated gif of black and white skeleton rotating, the acromion highlighted in red. Gif courtesy of wikidata.
The measurement should be taken across your back starting from one side, laying the tape on top of the muscle bulk of your shoulders, and going across to the other side. Do not take this measurement with the tape straight held away from your back- you want to be able to measure accurately how much space you’ll need inside the shoulder width of your soon-to-be-garments. If you are measuring yourself, I like to place my finger on the top of my shoulder and find the bend point when I raise my arm. You can then mark this placement with a small sticker, or a safety pin, so you can ensure your tape measure is placed correctly.
Please see the following videos for how to measure your across shoulder on both your body, and your patterns:
Why do you need these measurements, and how should you use them?
In my opinion, choosing a pattern size is hard enough! I like having the ability to choose based on your shoulder width — body circumference adjustments are easy enough to master (jump to the end of the post for some easy-to-follow resources). What’s really hard is messing with the armholes and neckline if the bust fits you but the shoulders don’t.
Now that you have both your body and pattern measurements, how do you know what will work and what won’t? If I may generalize, here’s a basic chart of what I *imagine* a good measurement range would be, based on the difference between the two measurements. This should give you an idea if the pattern size you’ve chosen will work, or if you should size up and down. Caveat — I can’t know what fabric you choose, or what pattern you have, so these are very general. Consider this a starting point for set-in sleeves. Drop shoulders will require you to use your imagination, and shaped raglans, dolmans, and grown on sleeves will be discussed in a future post.
Chart above is also linked here. Chart details difference garment types and a suggested range for a measurement difference between your pattern, and your body for a good starting point muslin.
If you end up with a shoulder width that is too small, it will pull your sleeve in towards your body, the seamline will sit inside your acromion, and you won’t be able to raise your arms straight out in front of you- the back body between your shoulder blades will appear to have horizontal pull lines between them. If you end up with a shoulder width that is too big, the shoulder seam will sit far out from your acromion, resulting in a droopy appearance with lots of folds at your underarms. Therefore, I am recommending that if the size you think you’d like to start with falls outside of the + / – range detailed in the chart, then you should consider selecting another size, for fear of ending up in a much larger or smaller size than would work using my patented ShoulderChoice method 😉
Now, with all that said, here are some go-to resources for Full and Small Bust Adjustments and grading between sizes:
Full Bust Adjustments:
– Curvy Sewing Collective
– Cashmerette
Small Bust Adjustments:
– Seamwork
– Closet Core Patterns
Grading Between Sizes:
– Cashmerette
– By Hand London
The next installment of The Great Shoulder Digest will touch on narrow and wide shoulder adjustments, shoulder girth, raglans / dolmans / grown on sleeves, and how it all works together to provide mobility. Look for this coming later this spring and as always, feel free to comment with questions or feedback. Thanks for reading!
Gabby is a technical designer, fit specialist, and prolific googler. She lives in Denver, raises moderately small people, reads, embroiders, makes, experiments, fails, learns, tries again. See her on instagram @ladygrift.
I think this is the One True Measurement I was missing for fitting correctly above the bust. I look forward to trying the method! ;D Thanks so much!
Awesome, I’d love to know how it works out for you! Thanks so much for reading 🙂
I’ve got several old Buttericks from the 80’s and 90s so the shoulder widths are all over. I’m going to give this a try. I have found over the past years I often need to use a smaller size in a very loose fitting or extended shoulder blouse, otherwise it dwarfs me. Thanks for the tutorial.
A suggestion for another important area of anatomy to discuss; necklines and the best way to redraw a neckline when needed.
Excellent, hope it works out for you! That’s a great suggestion, I’ll add it to my list 🙂 Thanks so much for reading!
Thanks for this. I went looking for image to save (jpg not animated gif) of arm and shoulder with acromion labelled, as this is very helpful for explaining where to start looking for hinge point. Then I added muscles to the search to see what the padded joint looks like.
What I discovered, though, was most of the images showed the muscle covered ball joint at the top of the arm protruding quite a ways out of shoulder/acromion, whereas my ball joint sits pretty much completely underneath the shoulder/acromion bones.
Now I have to think about how this impacts the shape of sleevehead I need for good fit, and whether I need all the standard shaping of the sleevehead at the top of the arm.
Your comment is why I push for patternmakers to study anatomy as well as dress-making! You may find because your joint sits differently, you need less cap height, however this is me gazing into a crystal ball 😉 I hope that this helps your fitting journey, and thank you for reading!
I started to look at skeletal structure when I was having trouble fitting panties. I discovered obstetrics and midwifery articles on variations in the shape of the pelvic cradle. I have to add 1.25″ to width of my crotch, and shorten it by 5/8″, making it likely I’m one of the 5% of women with Platypelloid pelvic cradle shape (shallow and wide – scroll down for image https://www.spinningbabies.com/blog-resource-library/birth-anatomy/ )
Then I started to think about why standard instructions for lengthening/shortening midway between underbust and waist, and waist and hip, were less than helpful.
I discovered designers draft for average 3″ gap between ribs and hips, whereas mine actually overlap (if I squeeze a ruler above my hip and under my ribs it has to slope down from back to front to fit between them – I have downloaded and edited these Wikipedia skeletons so I can illustrate what this shortened skeleton looks like https://en.m.wikipedia.org/wiki/File:3D_Female_Skeleton_Anatomy.png)
As a result it works better for me to shorten by just deleting an inch each side of the waist.
Muscles pulling on the ribs when there is a 3″ gap pull them in at the bottom. Muscles pulling on ribs when is no gap pull the ribs out at the bottom, flaring them out, so that underbust is smallest measurement, the bones spreading out to waist.
It’s been interesting sharing these insights on sewing and Designer group pages on FB, as these groups aggregate populations so that even skeletal variations that are a small percent of the population, show up in significant absolute numbers.
It’s so fascinating, isn’t it? So much of what are thought of as common adjustments might better be thought of as common techniques, leaving adjustment-territory to be way more customized based on actual bodies, rather than idealized ones. Love your contributions, thank you!
Awesome thank you! I’m so glad you included a recommendation for the relationship between body measurement and pattern/garment measurement, too. I know *about* ease, but I don’t know how much is needed, minimum, in various places for something to fit. So across the top of the shoulders, it should be a very close match.
(now to go measure various shirts I have as well; I think I have one that doesn’t dig into my armpits when I tie my shoes, while the rest do that or worse.)
You’re welcome! A lot of books say things like “measure yourself and then check the pattern” but don’t tell you how or why to do it- hopefully this is helpful! Re: shoulder ease, it’s more important for the seam to sit correctly for a set-in so that way the sleeve mobility isn’t inhibited 🙂 Thanks for reading!
Thank you much for this information on shoulders.
My pleasure! Thanks for reading 🙂
I really appreciate the work you’ve put into this post Gabby. Taking good measurements makes such a huge difference to the rest of the construction process. Thank you so much.
My pleasure, Maria! Hopefully this is helpful- thanks for reading, as always ❤️
Thanks for this great piece on shoulder measurement–it’s very helpful since shoulder seems to be my sewing bête noire. I’ve got broad sloping shoulders, but everything seems to be A-OK (no pulls, seam hitting correct shoulder line), until I add on the sleeve, then the back of the sleeve tends to migrate toward center back. I’ve tried every shoulder adjustment in Liechty, to no avail. Next stop: broad back adjustment (though I don’t really have a broad back). Ideas?
Oh good, thanks for reading! You might check that your sleeve cap isn’t too tight first- if the back armhole looks ok placement wise without the sleeve on, and isn’t pulling across the center of your back, you might increase the width of the sleeve cap/bicep and then re-check. If it’s still doing it and the sleeve is feeling ok, broad back all the way, baby!
Thanks very much! I’ll follow those great suggestion!