How to do a narrow or broad shoulder adjustment

HelenBlackwood Cardigan, Blackwood Sewalong, Fitting & Pattern Adjustments33 Comments

How to do a narrow or broad shoulder adjustment

How to do a narrow or broad shoulder adjustment

Today is the fourth installment in the Blackwood Cardigan Sewalong!  We are going to wrap up the adjustments portion of the process today with narrow and broad shoulder adjustments.  Tomorrow we will be cutting out the fabric and moving on to the actual sewing!

If you want to join in the fun, you can grab your copy of the Blackwood here!

Do you need a narrow or broad shoulder adjustment?  The indications for this change can be subtle. First, identify where your natural shoulder is. It should be right where your arm meets your shoulder socket, and you can usually find it by lifting your arm up and down and feeling around for the ‘hinge’. Now, try on your muslin and take a look at your fit. Is the shoulder seam sitting up from your natural shoulder? Are you seeing pulling lines radiating from the shoulder seam? You might want to try a broad shoulder adjustment. Is the shoulder seam lower than your natural shoulder? Do you have extra fabric pooling at the armpit or baggy sleeves?  You might want to try a narrow shoulder adjustment.

How to do a narrow or broad shoulder adjustment

If you are not making a muslin of your project, you can try on a previous make, like a t-shirt, and look at the fit there. Then, compare that pattern piece to your next project pattern piece to see if any adjustments might need to be made.

To determine the amount to adjust, I like to eyeball it. With your muslin on, take note of the distance from your natural shoulder seam to shoulder seam. This is your adjustment amount.

How to do a narrow or broad shoulder adjustment

Note: Also look for other indications of pulling or baggy fit. You may need to go up or down a size overall.

Let’s get started!

First, mark the seam allowance on your front pattern piece. Draw two lines. The first should go from the center of the shoulder to about 1/3 of the way down the armscye. The second line should be perpendicular to the first and go to the corner of the shoulder seam.

How to do a narrow or broad shoulder adjustment

Next, cut the lines, starting with the first. Cut down from the shoulder seam, stopping at the seam allowance marking. Clip into the seam allowance, leaving a little hinge of paper. Cut up into the second line, also stopping at the seam allowance and leaving a hinge.

How to do a narrow or broad shoulder adjustment

For a Broad Shoulder Adjustment

Swing the two triangles out to make some room. Place extra paper under your pattern piece and measure out from the seam allowance. Measure the amount you need to adjust and make a mark.

How to do a broad shoulder adjustment

Work with the hinged triangles to bring the seam allowance to meet the marking. Your triangles will be overlapping, this is what we want.

How to do a broad shoulder adjustment

Tape everything down and draw a straight line to true up the shoulder and a new curve to smooth out the armscye. There may also be a small gap in the upper corner to fill in.

How to do a broad shoulder adjustment

Cut off the excess paper and there you have it, you have made a broad shoulder adjustment! Don’t forget to make the same changes to both the front and back of your pattern! 

How to do a broad shoulder adjustment

For a Narrow Shoulder Adjustment

Measure in from the seam allowance and make a mark. Your measurement should equal your desired adjustment amount.

How to do a narrow shoulder adjustment

Work with the hinged triangles to bring the seam allowance to meet the marking. Your triangles will be spread apart, this is what we want.

How to do a narrow shoulder adjustment

Tape paper underneath to fill in the gap. Draw a straight line to true up the shoulder and a new curve to smooth out the armscye. There you have it, you have made a narrow shoulder adjustment! Don’t forget to make the same changes to both the front and back of your pattern! 

How to do a narrow shoulder adjustment


It is important to note that if you are making a large adjustment (more than 3/4″), you may want to consider adjusting the sleeve cap height to compensate for the amount added or removed from the shoulder. For a broad shoulder adjustment, you can remove height from the sleeve, and for a narrow shoulder adjustment, you can add height.

How to do a broad or narrow shoulder adjustment

I hope this post on how to do a narrow or broad shoulder adjustment has been helpful!

Do you have a different method for making this change? I’d love to hear about it!

About the author


Helen Wilkinson is the designer and founder of Helen's Closet Patterns. She also co-hosts the Love to Sew Podcast! Helen is obsessed with all things sewing and strives to share her passion and knowledge with the sewing community.

33 Comments on “How to do a narrow or broad shoulder adjustment”

  1. Thanks, Helen! I recently figured out I often need a broad shoulder (or maybe a square shoulder?) and have tried the pivot method from Pattern Fitting With Confidence by Nancy Zieman and Joi Mahon’s method of cutting and sliding. Both worked but I think the Zieman method matched up better with the sleeve head. I’ll try your method next, it looks much simpler than either. And thank you again for the use of your serger!

  2. This is brilliant! I have very narrow shoulders and always bodge it! Now just being pedantic, by how much would you raise the sleeve head when adjusting for a narrow shoulder. Thank you. Claudia

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  4. Hey all how much do you adjust the arm height by I’ve added an inch to a broad shoulder adjustment?

    1. Hi Samantha! I would take 0.5″ off the height of the sleeve cap in this instance. You may decide to take more off if the sleeve feels baggy in the arm.

  5. THANK YOU! I have narrow shoulders and have just about given up on sewing for myself because of having to practically redraft the pattern. At least, that was my opinion. More work than it was worth. I will try this and see how it goes. Thanks again.

  6. Thanks so much for this! I’ve been sewing for 10 months and just tried my first Tee shirt pattern. I’m now going to try version 2 with a broad shoulder adjustment.
    Love the podcast! I have learned SO much!

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  8. This post is extremely helpful. I wish I wouldn’t have seam ripped my entire muslin now… I am shaped like an upside down triangle!

  9. Thank you this was simple to understand. I need to reduce shoulder length by 2cm , what adjustment would I reduce sleeve cap, should it match 2cm or is there a formula or just an estimate?

    1. This is just an estimate if you have made an extreme adjustment to the shoulder, you may need to adjust the cap, too. The best way to figure this out is to sew a muslin with the new shoulder and see how the sleeve fits.

    1. Hi Barbara! I would sew a muslin with your shoulder adjustment first and see how it fits. If the sleeve looks like it is straining to sit at your shoulder – you will want to add to it. You can slash the muslin and see where it naturally wants to fall, then add that much!

  10. I found another way to narrow the shoulder. But I didn’t notice how to adjust the sleeve cap. My sleeve on purchased garments comes down onto my arm. 14″ from shoulder to shoulder. Breast is larger so to fit this the shoulders on purchased garments really does not work. I figured out I think I need to increase the sleeve cap but am not sure. Now I am but will have to figure out how much. It is easy to adjust the shoulder to arm pattern with SFD. Note: you did ask this question but not sure you want this info here? I do want to thank you for confirming that I have to add height to sleeve cap but not sure how much. I will do the shoulder arm the way you said and maybe that will give me an idea of how much I need to try to adjust my sleeve cap. I am guessing you are talking about notch to notch regarding the adjustment. If not please respond to this. I gave up sewing many years ago due to not having a clue as to how to make a pattern that will actually fit me. Thanks for all you do for people trying to make this adjustment. It was a hard to find answer for me. I am sure I need to adjust 1″-3″ if possible. I felt if I tried to just put the sleeve in without changing it, it would be at the wrong angle.

  11. The shoulder part of my blouse is tight on me. My shoulder is nearly 16inch and the blouse’s measurement is 14.4inch. Is it possible to loosen the shoulder of the blouse?

    1. Hi Lauren,

      You can try letting out the seam allowance if there is wiggle room there. You could also try to sew an additional piece onto the shoulder to extend it and a seamline there could look cool! If you are not a sewist, a tailor would be a great place to go and get an alteration assessed 🙂

  12. Hi Helen
    I find my sewn, sleeveless garments have excess fabric in the hollow of my front shoulder,chest area between shoulder and armhole – it’s as though I need a vertical dart in that area – HB 100, FB 110, S (from shoulder point to shoulder point) 34 with seam allowance. Even though I have boobs, its as though my upper chest is slightly hollow. Will the narrow shoulder adjustment work for me? Or is there another adjustment? Guthrie & Gharni slashed from shoulder to bottom of armhole and closed up the paper slash by about 10mm. Just worried this method might throw out the cut. Regards, Sandra

    1. Hi Sandra! Thanks for checking out this post. You might try sizing down in the upper bust and doing a small FBA to get rid of that excess fabric. I think the narrow shoulder adjustment is more about the width of your shoulders. You can also try adding an armscye dart to get rid of gaping in the armhole.

  13. Hi Helen, a lot of my patterns cut me under the armhole. How can I fix that? Just cut it deeper under the arm?

    1. Hi Riana,

      I would try lengthening the pattern across the chest so the armscye is deepened in the process. If there is a sleeve, you will need to add that same length to the sleeve cap.

  14. Hi Helen,

    Great tutorial. If a person needs both a narrow shoulder adjustment and an FBA, which would you recommend doing first? Or would it be better to size down more in the hope of fitting the shoulders and do a bigger FBA?

    I also have the same issue as the poster above, where I end up with the bust and shoulder widths correct, but excess fabric in between. Would doing an SBA before the FBA remove any allowances made for a B cup bust that sits higher than mine?

  15. Hi Helen. This is a great help how ever I always find raglan and drop sleeves leave too much fabric too low under my arm and at the side bust area. I’ve had issues with the Fringe dress and recently the Wilder gown. Both beautiful dresses but if I take it in under my arm then it’s too tight across my shoulder blade and middle back area. How do I fix this.

  16. So useful but if I have a protruding shoulder and a narrow shoulder which alteration should come first? Your explanation on adjusting for narrow shoulder is brilliant

  17. I love this post! Thank you for including instructions for both narrow and broad shoulder adjustments. This is so helpful for people who have trouble finding patterns that fit them well.

  18. Thank you so much! I couldn’t find this in any of my patterning books. The images are easy to understand.

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