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On Fitting Sleeves

Sewers I meet through my seminars always tell me they can’t get their set-in sleeves to fit. They’re too small, too tight, don’t allow mobility… Having compared the sleeves and armholes provided in current commercial patterns to those typically used in ready-to-wear, I’m not surprised. I’ve found that almost all ready-to-wear jackets and blouses have lower armholes and wider sleeves than the typical pattern for a similar garment. It’s also common for patterns to be wider across the back than comparable ready-to-wear in the same size. But such observations can’t do more than point the struggling fitter in the general direction of a cure. The most useful place to start solving a problem with fitting sleeves, is with a bit of “research” shopping-try on as many similar garments as necessary until you find one that fits the way you want only in the sleeves and shoulders. Don’t look for a garment that fits everywhere-you may not find it-you’re just looking for the sleeves and shoulders. I’ll describe how you can turn such a try-on discovery into a lifetime fitting aid.


More on sleeves:

• How to Fit Sleeves
• How to Draft a Square Sleeve Cap
• A Forgiving Bias-Cut Sleeve
• Add a Fluttery Sleeve to a Sleeveless Garment
• Add a Quilted, Zippered Cuff

Don’t measure yourself, measure what fits

I’ve met hundreds of women who can tell me their measurements, but don’t know the measurements of garments that fit them the way they like. I propose the following radical but practical notion: It’s more useful for a sewer to know what works for her than to know what her own measurements are. (Sleeves are not the only garment details for which this idea is useful.) Once you’ve located your Holy Grail set-in sleeve or sleeves (a jacket sleeve and a blouse sleeve cover the set-in territory for me), all you need to do is measure it carefully in the relevant areas (including the garment’s upper back, which controls the freedom of movement), then make sure that all your future garments with similar sleeves have the same measurements.

The drawings at the bottom of p. 55 (Threads #107) show what to measure on the garment, and the drawings on pp. 56-57 show how to use these measurements to alter your pattern sleeves, pattern armholes, and pattern backs to match your ideal.

If you discover that your pattern is more than an inch or so off from your measured ideal, use a closer size-this method is not meant for resizing a whole pattern. Otherwise, as far as all standard set-in sleeve styles go, it’s really that simple. Good hunting!

Measure your garment

The text and drawings that follow explain what to measure on your garment.

On the sleeve fitting measurements

On the sleeve

1. Cap line circumference: Measure around the sleeve horizontally at the underarm level.

2. Cap height: Measure from the cap line vertically to the top of the armhole.

On the body

3. Armhole: Measure the arm-hole seamline. (This is optional; use it only for comparison when trying on garments and to see how close your starting pattern is to your ideal.)

4. Shoulder width: Measure the back horizontally from the end of the shoulder seam to the opposite end. Divide the measure in half, then compare it to the pattern.

5. Upper back width: Measure the back horizontally from armhole to armhole, about 8 inches down from the shoulder. Divide the measure in half, then compare it to the pattern.

6. Back width: Measure the back horizontally from underarm to underarm. Divide the measure in half, then compare it to the pattern.

measure back width on the body

Correct your pattern

Now that you’ve measured your garment, you can now use these measurements to alter your pattern sleeves, pattern armholes, and pattern backs to match your ideal.

The sleeve cap height

Before you begin, find the ease allowance in your original pattern by subtracting the length of the sleeve cap seamline from the length of the total armhole seamline. All diagrams are without seam allowances.

Slash the sleeve cap horizontally above the notches. Spread or overlap the pieces by the amount needed to make the cap height match the measured garment cap height. Blend the curve across the gap or overlap to create a smooth seamline. Measure the corrected seamline; subtract the original ease allowance.

Sleeve cap height adjustments for fitting sleeves

Armhole designer curve for fitting sleeves

The armhole

Alter the armhole by raising or lowering the underarm seamline by the same amount you add to or subtract from the sleeve cap height.

1. Measure and mark the amount of your alteration on the side seam. Find the section of a designer’s curve that matches the armhole curve at the underarm.

2. Slide the designer’s curve down, without pivoting, to reposition the armhole shape at the marked point on the side seam. Draw the new seamline.

3. Use other sections of the designer’s curve as a guide to blend the new seamline upward into the existing seamline.

4. Check that the new armhole seamline length equals the new sleeve cap seamline length minus the original ease allowance.

The back

Compare all three garment back measurements with your pattern; alter all three areas with a single adjustment.

To make the back uniformly wider or narrower: Slash the pattern vertically from the midpoint of the shoulder seamline to the hemline. Spread or overlap the pieces. Blend the shoulder seamline across the gap or overlap, and then alter the front shoulder seamline to the same length by extending or reducing it at the armhole.

Uniformly spread or overlap to widen or narrow

To make the back progressively wider or narrower: Slash the pattern vertically from the midpoint of the shoulder seamline to the hemline. Pivot the side-back piece from the shoulder or hemline as needed to adjust the width of the opposite edge. If pivoting from the hemline, blend the shoulder seamline across the gap or overlap, and then alter the front shoulder seamline to the same length by extending or reducing it at the armhole.

pivot the side piece for fitting sleeves

To make the back selectively wider or narrower: Use or create a seam at the center back or use a princess seam to subtract or add width selectively across the back but not at the shoulder or the hemline.

Selectively widen or narrow the back

The sleeve cap line

Before you begin, measure the width of the sleeve on the hemline.

1. Slash the sleeve from the hemline to pivot positions on the cap seamline above the notches as shown. On a two-piece sleeve, adjust the upper sleeve only (see the instructions and drawing below).

Slash cap lines

2. Spread (or overlap) the sections equally at the hemline until the cap line is equal to your measured garment cap line.


3. Redraw the underarm seamlines, tapering equally, to return the hemline to its original width. Draw a straight hemline across the spread (or overlapped) sections.

Taper for fitting sleeves

For a two-piece sleeve, slash each outer section on the cap line, leaving a hinge at the outside edge, and pivot the lower portion to abut the inner section at the bottom edge. Redraw the hemline.

Pivot for fitting sleeves

To find the cap line on a two-piece sleeve: Align the under sleeve with the upper along one seamline at the cap edge. Draw the cap line perpendicular to the upper sleeve lengthwise grainline and touching the lowest point of the underarm curve on the under sleeve.

Cap line for fitting sleeves

Peggy Sagers writes and designs patterns in Dallas. You can reach her at www.silhouettepatterns.com.

Illustrations by Linda Boston

by Peggy Sagers
excerpted from Threads #107, pp. 55-57

Previous: A New Way to Fit Sleeves Next: How to Modify Sleeves for Better Arm Mobility


  1. jjgg | | #1

    Lower armholes will cause less movement. A higher armhole allows one to raise their arm without pulling up the side seams of the garment. Also, I think part of the problem home sewers have with sleeve fitting is the poorly drafted commercial patterns (I am referring to the 'big 4' here only). Generally they have very balanced sleeves - front and back sleeve cap matches. There is also way way too much ease in the sleeve cap on these patterns.

    RTW may allow more movement with the lower armholes, but they also generally fit rather poorly.

  2. RosemaryB | | #2

    I have a problem that has been on going for years. I love consignment shops and have either run on or bought things that were wonderful or just a terrific deal but they have been a size or two too large. The only item i have trouble taking in are blouses, no problem with the sides but then the shoulders look all goofy. I am afraid of taking off too much for obvious reasons. Please Help !!!!!!!!! Thanx

  3. User avater
    GreenTrunkDesigns | | #3

    OH, I need this info bad! Thanks for sharing

  4. Candy_s | | #4

    Thanks I needed immediate Designer into fleece vest. This is the beginning and it looks like add 3" to capline then shorten to get this into too big armscye. It will be completed within two weeks.

  5. LBeveryday | | #5

    This information has been very helpful. Thank you for posting!! I had to favorite this article:)

  6. KiwiLee | | #6

    jjgg: I agree about the way the pattern companies are balancing their sleeves. I suspect its because the proliferation of knit fabrics means the stretch "forgives" lack of good fitting - ie, stretch means one size fits nobody.

  7. calebsgran | | #7

    Peggy:This an excellent tutorial. Thank you so much.

  8. user-6800598 | | #8

    Your advice is helpful. If, as you say, sleeve caps are too balanced, how would you correct that? And just how much ease would you suggest, say, on a simple boxy suit jacket?

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