Tilly and the Buttons: How to Do Narrow and Wide Shoulder Adjustments

Do you usually find that your garments are too small or too big across the shoulder? If so, you might want to consider doing a narrow or wide shoulder adjustment. It’s Nikki here, Product Manager at Tilly Towers, and I’m here to show you two ways to adjust the shoulders on your pattern pieces to help you get a good fit – one “quick and dirty” method, and one more involved and more accurate method.

How do I know if I need a shoulder adjustment?

But first, if you want to know whether you need a narrow shoulder adjustment you’ll have to know where the shoulder should actually sit.

As with most things when it comes to sewing, the answer to this depends on the style and fit of the garment you’re making. Some patterns are designed with a drop shoulder seam, like the Nora top, whilst others intend for the shoulder seam to sit directly on the shoulder socket, like the Indigo top and dress. If you’re unsure, have a good look at the pattern technical drawings – this should tell you what you need to know.

If the pattern is intended to sit on the shoulder socket, you’ll need to know how to find out where this is on you. Luckily this is really easy to do. Bend your arm at the elbow and lift it up and down to the side (I like to imagine I’m playing the bagpipes if that helps!) and feel with the fingers on your other hand for where the “hinge” is, where the arm meets the shoulder socket. As you move your arm up and down you’ll be able to feel where the socket moving. This point is where the shoulder seam should sit.

To find out whether the shoulder seam will sit in an optimum spot for you personally, I thoroughly recommend making a toile (a muslin) first, or at least a wearable toile. Mark the armhole seam allowances on the toile and take a look in the mirror to see if the seam (the seam allowance line) is sitting roughly on your shoulder socket.

If it’s sitting beyond the socket and is migrating down your arm, this indicates that there is too much length in the shoulder seam and you need a narrow shoulder adjustment. If it’s sitting further back towards your neck, and most likely feeling a bit tight, then this indicates that the shoulder seam on the pattern is too short for your shoulders and you need a wide shoulder adjustment.

Measure the distance between the seam line and the shoulder socket – that’s the amount you either have to add or subtract from your shoulder seam. You can use the below methods to adjust the shoulder seam up to around 2cm (3/4in). If you want to add or subtract any more than this amount, you’ll have to also adjust the sleeve head to make it bigger or smaller so it matches the new armhole shape.
I’m going to show you two different ways of doing a narrow and wide shoulder adjustment. The first method is super speedy, but may slightly alter the length of the armhole. Because of this, I’d recommend using this method for small adjustments made on knit garments, or for patterns that have ease or gathering in the sleeve head – you can ease in any excess fabric where needed.
For a more accurate technique, use the more involved “slash and spread” method outlined further down the page, which will keep the armhole seam the same length. This is best for sleeves in woven garments with little to no ease.

I’m going to show you two different ways of doing a narrow and wide shoulder adjustment. The first method is super speedy, but may slightly alter the length of the armhole. Because of this, I’d recommend using this method for small adjustments made on knit garments, or for patterns that have ease or gathering in the sleeve head – you can ease in any excess fabric where needed.

For a more accurate technique, use the more involved “slash and spread” method outlined further down the page, which will keep the armhole seam the same length. This is best for sleeves in woven garments with little to no ease.

On the front bodice pattern piece, measure in from the armhole end of the shoulder seam the distance you want to reduce the shoulder width by. Square off the corner into a right angle, then redraw the rest of the armhole curve, blending into the original armhole.

Transfer any markings from the original armhole to the new line, such as notches.

Do the same adjustment on the back bodice to make sure the shoulder seams match up.

And that’s it! Talk about speedy.

Wide shoulder adjustment – the quick and dirty way

Glue or tape a piece of paper underneath the armhole on the front bodice pattern. Measure out from the armhole end of the shoulder seam the distance you want to increase the shoulder width by. Square off the corner into a right angle, then redraw the rest of the armhole curve, blending into the original armhole.

Transfer any markings from the original armhole to the new line, such as notches.

Do the same adjustment on the back bodice to make sure the shoulder seams match up.

And you’re done! Told you it was quick 🙂

The “slash and spread” method

Whether you’re doing a narrow or wide shoulder adjustment, the process starts in the same way. Once you’ve followed these initial steps, jump to either the narrow or wide shoulder adjustment section to complete 🙂

Start by marking the centre point on the shoulder seam and the seam allowances on the armhole and shoulder seam (15mm / 5/8in in from the edge). Draw a line from about a third of the way down the armhole to the centre point on the shoulder. I’ve shown this here with a green line. Draw a perpendicular line from the top corner, where the armhole meets the shoulder, down to meet the green line. I’ve shown this with a red line.

We need to create two “hinges” on the pattern which will allow us to move the paper and manipulate the pattern piece without it separating. This is achieved by cutting down a line before stopping at a designated point (in this case, the seam allowance), and then cutting down the line from the other end and stopping a smidge before you cut the pieces in two. Don’t be shy about getting right up to the seam allowance line, but try as hard as you can to not actually snip through!
The first step in the hinge making process is to snip into the pattern from the armhole edge to just before the seam allowance. Do this again for the top corner where the armhole meets the shoulder.

The first step in the hinge making process is to snip into the pattern from the armhole edge to just before the seam allowance. Do this again for the top corner where the armhole meets the shoulder.

Now we need to cut into those lines from the other end. Start at the shoulder seam and cut down the green line, stopping just shy of the seam allowance markings to make a hinge. Cut up the red line, again stopping a smidge before the seam allowance markings.

Be very gentle and with the pattern piece as it’s very delicate. If you do end up ripping through one of the hinges and separating a pattern piece it’s not the end of the world – stick it back together with some sticky tape and re-cut the hinge.

Narrow shoulder adjustment – slash and spread method

A narrow shoulder adjustment shortens the shoulder seam, so using these hinges we want to overlap the pattern pieces to make this seam smaller.

On the seam allowance line on the shoulder seam, mark where you want to overlap the pattern pieces. The distance between the edge of the cut pattern piece (where the green line intersects the seam allowance) and the marking is the amount you’ll decrease the shoulders by e.g. 15mm (5/8in).

Gently move the shoulder seam so that the seam allowance line on the triangle meets the marking. You’ll notice that the bottom parts of the triangles will overlap the pattern piece, whilst there will be open space between the red line. Tape or glue down.

Slide some paper underneath your pattern piece to cover the gap between the triangles and stick the pattern piece to the paper. We also need to re-draw the shoulder and armhole seams to make them nice and smooth.

Firstly, re-draw the shoulder seam to make it straight again. Start at one end of the seam and draw a straight line to the other end.

Re-draw the armhole seam around the place where we snipped up to the seam allowances. You don’t need any fancy equipment here, a smooth line drawn by hand will suffice, although you might want to use a French curve or pattern master here if you have one. Cut away the excess paper.

Congratulations, you have successfully done a narrow shoulder adjustment! Don’t forget to do the same adjustment to the other bodice piece so that the seam lines are the same length when you sew them together.

Wide shoulder adjustment – slash and spread method

Slide a piece of paper underneath the pattern piece and stick down the neckline side only. Don’t stick the hinged triangles down as we need to move them!

Extend the seam allowance line and mark how much you’d like to widen the shoulder seam by. A marking 15mm (5/8in) away from the edge of the pattern piece will mean the shoulder seam will be 15mm (5/8in) longer after the adjustment.

We now need to re-draw the shoulder and armhole seams to smooth them out after all that pivoting.

Firstly, re-draw the shoulder seam to make it straight again. Start at one end of the seam and draw a straight line to the other end.

Re-draw the armhole seam around the place where we snipped up to the seam allowances. You don’t need any fancy equipment here, a smooth line drawn by hand will suffice, although you might want to use a French curve or pattern master here if you have one. Cut away the excess paper.

And that’s it! You have successfully done a wide shoulder adjustment. Don’t forget to do the same adjustment to the other bodice piece so that the seam lines are the same length when you sew them together.

Liked this post? Check out How to Do Bust Adjustments on a Bust Darted Bodice and How to Combine Pattern Sizes.