And so, we enter the twilight of the Great Shoulder Digest: here are Parts One and Two. In Part Three, I discuss narrow shoulders, broad backs, why sleeve cap widths shouldn’t be ignored, the Dread Pirate Raglan, grown on sleeves, and a few last bits & bobs.
Narrow Shoulders and Broad Backs
Hello, I see you! I’ve gotten plenty of questions on how to make these adjustments, and here are some resources for going either way (as always, the ones I found to be clearest and easiest to follow):
- Helen’s Closet How to do a narrow or broad shoulder adjustment
- By Hand London Broad Back Adjustment
- Deer & Doe Broad Back Adjustment (Set-in & Grown-on)
- Oliver + S How to do a narrow shoulder adjustment
- Curvy Sewing Collective Tutorial: Narrow Shoulder Adjustment
How do you know if you need an adjustment? In other words, I’ve told you what to do, but…WHY?!?
If you’re not referring to my ShoulderChoice guide from the previous digest, you may find yourself in a situation where the shoulders on your garment are sitting much too far out, or much too far in. This is very easy to see if you fit your muslin without the sleeve first, to make sure your seamline is sitting in the correct spot. How do you know the correct spot? A good traditional set-in sleeve armhole will neatly encircle your arm at the body join, and the top of the armhole seam will sit roughly over the acromion, or shoulder joint, as discussed last time. If it doesn’t, it should be pretty clear to see if you need to move the shoulder in or out.
I know, I know, muslins are such a pain, right? But checking them before cutting your real fabric is so valuable, and especially checking them without the sleeve, if you’re not worried about stretching anything out, before popping the sleeve on.
In terms of how a muslin or garment feels, with a sleeve on: if you have narrow shoulders, your shoulder seams will tend to fall off your shoulder, and your sleeves will droop. If you have broad shoulders/back, you’ll have horizontal pull lines on your garment between your shoulder blades, your armhole seams will pull in towards your body, and your sleeves may feel tight.
Now, the tricky part. If you are fitting a muslin with the sleeve on, here are some situations that might FEEL like you need to make a broad back adjustment, when in fact you might not:
- The sleeve cap is too tight.
- The armhole is too low.
You can tell when these situations are happening, by checking a few things:
- The muslin without the sleeve, to check armhole placement on your body.
- The sleeve cap width approximately 2″ down from the top of the seamline, horizontally. It’s good to have an idea of this measurement, as you keep sewing different styles, you can track and compare to see what’s working for you using different fabrics on similar styles. On body, if the sleeve cap is tight, you’ll see it straining at the armhole seams, with the point of the draglines at the seam and the coning releasing at the overarm/shoulder. It’s a similar visual when the bicep is too tight: point of draglines at the seam, cone release at the overarm.
- The armhole is too low. When this happens, the bifurcation point of the armhole sits below your arm/body join, and will prohibit you from being able to raise your arms. Obviously, there are styles with drop shoulders and low armholes on purpose, but this is something to watch out for on wovens and outerwear. I’m a fan of a higher armhole myself.
Of course, if your sleeve is not too tight, the armhole is not too low, and your problem truly lies in the bodice of your garment, adjust away, dear friends!

Total Shoulder Girth (sometimes referred to as total shoulder circumference)
Why on earth would you want to know this measurement? I’ll refer you to the above—this is a handy shortcut to being able to tell in advance whether you’ll need to make some adjustments before even cutting a muslin.
You shouldn’t need a fitting buddy to take this measurement; just make sure the tape is relatively level and isn’t too low. You’ll want to loop the tape around your shoulders, around 2″ down, and horizontally around your back and front chest. The photos below are just an example of the tape placement on a mannequin (obviously, I can’t use this particular measurement, because I haven’t made arms for her yet, but I will use my on-body measurement when I do, to make sure the arms aren’t too big/small.)

So now that you have that measurement, you can use it to get a general idea of what your shoulder circumference sweet spot is: take a pattern that fits you well and measure across the front, across the sleeve cap, and across the back. Add it all up, and compare! Then, you can aim for a similar range (if you had a difference between the two), and you will easily be able to tell when something won’t work as drafted.
*Don’t forget—sleeve cap x 2, and if your front/back pieces are cut on the fold, you will double them as well to get the total circumference.
**You can use this for both knits and wovens, as long as you’re keeping track of similar textile qualities (stretchability, etc.).

Raglans & Grown On Sleeves
First things first. Where, exactly, IS the shoulder point on a raglan? This is where a muslin is extremely helpful! You don’t have to cut a whole muslin—you can do a half mock-up (shortened front/back panels), but you should make sure that the muslin has both sleeves attached so you can really feel any stress points. I *heartily* recommend a muslin for raglans. They aren’t very complicated once you understand the shape, but they’re a much bigger pain in the rear than a regular set-in sleeve because they encompass the shoulder as well as the sleeve.
Put the muslin on and feel for your shoulder joint/acromion. Add pins, or otherwise mark your muslin at that spot, and now you’ll be able to add that placement onto your pattern for adjustment purposes. (Of course, if you’re working on something with no negative ease and you know your across shoulder measurement, you can measure your pattern from the Center Front/Center Back to that shoulder point and mark it that way, as well.)
(Image above uses a photo of a RTW raglan blouse from ELOQII.com).
I think it’s really important to know where your shoulder will sit inside of the pattern, because while pattern companies may tell you the height and cup size of what their block draft is, it’s much less common (if any do, at all) to share information about their block’s shoulder widths. Especially with a raglan sleeve—sometimes it’s extremely hard to tell by the pattern shaping where the shoulder point is.
That all said, here are some resources for fitting raglan sleeves—the key here is to see where you are getting stress/draglines or collapsing and where the pattern needs to be released/reduced. (Again, it’s really helpful to be able to mark and cut on a muslin for transferring your fit adjustments to a pattern.) Personally, I find slashing and spreading raglans to be fussy and frustrating; it can be easier just to work from measurements and reshape, making sure your new seamlines walk and sew together.
- Collete Narrow shoulders on a raglan
- Closet Core Patterns Raglan adjustments for a sleeve with a center seam
- Alexandra Morgan Adjusting shoulder slopes on a raglan with a dart
- Alexandra Morgan Adjusting for forward shoulders on a raglan with a dart
So that’s the hard stuff! Grown-on sleeves can be adjusted in much the same way as set-in sleeves, if you need to reduce or increase the shoulder widths. And you can use either method detailed above for raglans, as a way to measure where your shoulder placement would be in a grown-on sleeve.
Last Bits & Bobs
Of course, there are also rounded backs and hollow shoulders, which affect the fit of garments through your shoulders—I didn’t forget about you!
Rounded backs are very common. What happens is more length is needed through the back panel of the garment in order to accommodate for a more curved shape through the upper back/shoulder blades. This is a standard hallmark of aging—skeletons tend to hunch forward more and more as time goes on, due to things like osteoporosis or loss of muscle; however, this also can occur with things like scoliosis, or simple poor posture.
Forward shoulders are another extremely common adjustment. I might argue that forward shoulders are a feature of fitting for a) people with breasts, since a hollow is formed between the front shoulder and the start of the breast tissue, and this will cause garments to shift backwards, and b) people these days tend to hunch more forward due to using various technologies. The forward shoulder hollow can get more exaggerated based on the size of the bust, and how high the breasts sit on the body (naturally or with help from undergarments). Patterns and RTW are usually drafted on people around 5’8″ with a B cup—but the average American female is only 5’4″ (and even shorter in some parts of the world) with a DD cup—so you can see why patterns are just a set of instructions, and expecting garments to fit correctly out of the envelope on the first try is…perhaps a bit pie in the sky.
In conclusion, please see the below links for more clear and well-reasoned resources for your viewing pleasure:
- Curvy Sewing Collective’s Tutorial How to do a High Round Back Adjustment.
- Melly Sews Shoulder Fitting Adjustments When Sewing.
- Maria Denmark Forward Shoulder Alteration.
- In House Patterns Forward Shoulder Adjustment Two Ways.
- Colette Patterns Sewalongs Shoulder Adjustments.
- Dream Cut Sew Adapting Sleeve Patterns for Square or Rolling Shoulders.
- Sarah Veblen’s Complete Photo Guide to Perfect Fitting.
Thanks for reading the Great Shoulder Digest! If you have any other interesting resources to share, please post them in the comments. I’d love to see what works for you 🙂
Gabby is a technical designer, fit specialist, and prolific googler. She lives in Denver, raises moderately small people, reads, makes, experiments, fails, learns, and tries again. See her on instagram @ladygrift.
Thank you so much! I was trying yesterday to research how to adjust the shoulders on a raglan. This information and round-up of other articles is so helpful.
Oh good, I’m glad to hear it! Thanks for reading 🙂
This lucid explanation and brilliant measurement instructions are exactly what I needed! HUGE thanks!
You’re very welcome! Hope it is useful ❤️
Thank you so much for this series, Gabby. I’ve thoroughly enjoyed it and bookmarked every post for future reference. You’re a treasure trove of fitting information!
Awesome, that’s great to hear! Hope it ends up being helpful- thanks for reading! ❤️
When you say an armhole that is “too low” or that you prefer one that is “high”, where does the underarm seam sit in relation to your armpit, and the pectoral muscle that sits in front of the hollow of the armpit? I’ve never managed to find an explanation that makes sense to me, only instructions to measure, for example, the height of the arm hole. Ok sure, I can measure to any point under my arm, but which point will get me the best fit?!
Great question! Of course this is one of those “it depends on the style” answers, but for a basic set-in sleeve I prefer an armhole that sits roughly 1″ish from the armpit where the arm meets torso. This can be lower for raglan styles and layering pieces, but for set-in sleeved tops, the lower the curve of the armhole goes, the less mobility you’ll have, because of where the sleeve has to meet the body of the garment. (Unless it’s a really loose fit throughout both body and sleeve, of course). There’s a really good post about Chanel jackets and some armhole comparisons over on Cloning Couture you might like- there are several photos showing different armholes and it really makes a difference to see the patterns laid out.
https://cloningcouture.com/2014/08/04/chanel-and-the-sleeve/
And another article from the Smithsonian with a photo of Chanel herself, demonstrating the sleeve mobility:
https://www.smithsonianmag.com/arts-culture/top-10-chanelisms-cocos-wise-words-to-mark-her-birthday-28018452/
Hope that helps!
Interesting, thanks for the links. Right now I’m working on a basic sloper (tough measuring myself for some of the info I need, but I will get there…) so I probably want an “as high as still fits” armhole, which I can lower if the style wants it.
Putting this info together with all the other stuff I’ve been collecting… the high chest measurement which generally is taken as high as you can get the tape with your arms by your sides (right?) – would that height be the “where the arm meets the torso” point you mention? Or are you talking about the point inside the armpit as “where the arm meets the torso” and the 1″ below that is to allow for the pectoral muscle, and intended to match with the height of the high chest measurement?
Ah yes, for a sloper the higher the better.
So, the high chest/bust- you want to take that at the point on your chest just above or at (depending on how much vertical space you have) where the breast tissue starts- the idea to get a good comparison of ribcage without breast, and ribcage at fullest breast (full bust/chest). Again, depending on where that is on you, it may sit right up where the arm meets torso. If you have a very full bust, your tape will probably be higher up in the armhole than if you have a flatter chest. I wouldn’t necessarily use the high chest for an armhole depth point for that reason.
Now, if you wanted a good idea of an armhole depth, you can push the tape up to the arm/torso meet point, and then use a second tape, or a safety pin to mark where that hits on your front body, and measure down from your highest shoulder point. Then you will have a starting point for the armhole depth, and you can add 1″ or so to that to get an armhole draft going. Hopefully that makes sense- it’s a bit harder to type it out than to see photos, if you want to message me on IG I’m happy to talk further about armholes (with pictures!) haha.
That would be fantastic, thank you! I’ll send you a message on IG 🙂
Dear Gabby, I want to thank you so much for this series, I’ve learned so much!
Oh good, I’m so glad! Thanks for reading ❤️