Sewing sleeves is the part that stops most people—but the process is straightforward once you know the order
A shirt with sleeves requires you to sew the sleeve cap (the curved top part) into the armhole of the body, then finish the sleeve seam down the underside of your arm. The sleeve cap is slightly larger than the armhole opening, so you ease the extra fabric in as you sew—that's the only tricky part, and it becomes routine after the first one. You'll sew the body pieces together first, attach both sleeves, then sew the side seams and sleeve seams in one continuous line down each side.
This guide assumes you have a pattern, fabric cut to size, and basic sewing supplies: thread, pins, scissors, an iron, and a sewing machine. If you're working from a commercial pattern, follow its layout and grain line markings—they matter for how the fabric hangs.
Key Takeaways
- Sew the shoulder seams of the body first, then attach both sleeves before closing the side seams, so you can reach into the armhole while pinning.
- The sleeve cap has more fabric than the armhole, so you pin it in quarters and ease the fullness as you sew, using a slightly shorter stitch length to control the curve.
- After both sleeves are attached, sew the side seam and sleeve seam as one long seam from the cuff to the underarm, which creates a stronger, straighter line.
- Press the seam allowance toward the sleeve after attaching it, then press the finished sleeve seam flat to set the stitches before hemming.
- A walking foot or ballpoint needles help prevent skipped stitches and puckering on knit fabrics; woven fabrics are more forgiving.
Prepare the body and mark the armholes
Cut out all pattern pieces and transfer any markings from the pattern to your fabric using tailor's chalk or a fabric pen. Mark the top of the sleeve cap (usually a notch or dot) and the shoulder point on the armhole—these are your anchor points for pinning. Sew the front and back body pieces together at the shoulders using a straight stitch with 5/8-inch seam allowance, which is standard for most patterns. Press the shoulder seams open or to one side, depending on what your pattern says.
Try the body on inside-out to check the shoulder seam sits where your shoulder bone is. If it's too far forward or back, you can adjust on the next shirt—for now, note where it fell. The armhole should feel comfortable and not pull when you raise your arm.
Pin the sleeve cap into the armhole
Turn the body inside-out and lay it flat. Place the sleeve inside the armhole with right sides together (the pretty sides facing each other). The underarm seam of the sleeve should line up with the side seam of the body. Pin at this point first.
Next, pin the top of the sleeve cap to the shoulder seam. Then pin at the front and back armhole notches—these divide the armhole into quarters. You now have four anchor pins. Between each pair of anchor pins, add more pins every inch or so, easing the extra sleeve fabric as you go. The sleeve cap will bunch slightly between pins; that's correct. Smooth it gently with your fingers as you pin, but don't stretch it.
Check that no wrinkles or tucks are caught under the pins. The body fabric should lie flat against the sleeve, and the sleeve should curve smoothly into the armhole without puckers.
Sew the sleeve cap with a short stitch length
Set your machine to a stitch length of 2.0 to 2.2 mm—slightly shorter than your normal 2.5 mm. This shorter stitch helps the fabric ease smoothly and prevents puckering. Sew slowly, keeping the presser foot flat and the fabric layers even. As you approach each pinned section, remove the pin just before the needle reaches it, not before.
Sew all the way around the armhole, then backstitch at the start and end. Remove the pins as you go. Once you've sewn the entire cap, try the shirt on inside-out. The sleeve should sit smoothly in the armhole with no wrinkles or pulling. If you see puckers, you can carefully pick out the stitches and re-sew that section with more easing.
Press the seam allowance toward the sleeve using the tip of your iron, following the curve of the armhole. This sets the stitches and helps the seam lie flat.
Attach the second sleeve the same way
Repeat the pinning and sewing process for the other sleeve. Pin in quarters, ease the cap, and sew with the same short stitch length. Press this seam allowance toward the sleeve as well. Both sleeves should now be attached and the armholes should feel symmetrical when you try the shirt on.
If one sleeve sits higher or lower than the other, check that the shoulder seams are in the same place on both sides and that you pinned the sleeve caps at the same points. Small differences even out once you wear the shirt a few times, but large ones mean re-sewing one sleeve.
Sew the side and sleeve seams as one continuous seam
Turn the shirt inside-out and lay it flat. Line up the underarm seam of one sleeve with the side seam of the body. Pin from the cuff all the way up to the underarm, then continue pinning up the side seam to the hem. You're creating one long, straight line from the cuff to the bottom of the shirt.
Sew this seam with your normal stitch length (2.5 mm), backstitching at the start and end. This single continuous seam is stronger and straighter than sewing the sleeve and side separately. Press the seam open or to one side, depending on your pattern. Repeat for the other side.
Try the shirt on right-side-out. The sleeves should hang straight down from the shoulder, and the side seams should run vertically from your armpit to your hem. If a seam twists or pulls, you may have sewn it at a slight angle—you can pick it out and re-sew.
Finish the sleeve hems and cuffs
Measure the sleeve length from the shoulder seam to where you want the cuff to sit (usually at your wrist bone). Mark this length on both sleeves with pins or chalk. Trim the excess fabric to 5/8 inch below the mark, then fold the raw edge up 1/4 inch and press. Fold it up again 1/4 inch and press, creating a double-fold hem. Sew this hem with a straight stitch close to the inner fold, backstitching at the start and end.
Alternatively, if your pattern includes a cuff piece, sew the cuff to the sleeve opening with right sides together, press, fold the cuff to the inside, and topstitch it down. Cuffs are more formal and require more steps, but they're more durable than a straightforward hem.
Press all hems and seams flat with your iron set to the appropriate temperature for your fabric. This sets the stitches and gives the shirt a finished look.
Frequently Asked Questions
Why does my sleeve cap pucker even though I pinned it carefully?
Puckering usually means you're pulling the fabric too tight as you sew, or your stitch length is too long. Try a 2.0 mm stitch and sew more slowly, letting the machine feed the fabric. If the puckering is only in one spot, you can pick out that section and re-sew it with more easing in that area.
Can I attach the sleeves before sewing the shoulder seams?
No—you need the shoulder seams sewn first so the armhole is the correct size and shape. If you sew the sleeves before the shoulders, the armhole will be too large and the sleeve won't fit properly.
What if my sleeve twists or doesn't hang straight?
This usually means the underarm seam of the sleeve isn't aligned with the side seam of the body, or the sleeve cap wasn't eased evenly. Check that both anchor pins (underarm and shoulder) are in the right place, and that you eased the cap the same amount all the way around. You can pick out the seam and re-sew it.
Do I need a walking foot to sew sleeves?
A walking foot helps prevent puckering on knit fabrics and thick materials, but it's not required for woven cotton or linen. If you're sewing knits, a ballpoint needle and a walking foot together make the job much easier. For woven fabrics, a regular needle and presser foot work fine.
How do I know if the sleeve length is right?
Wear the shirt and let your arms hang naturally. The hem should sit at your wrist bone or just above it. If you're between sizes, aim for the wrist bone—sleeves that are too short look unfinished, and sleeves that are too long bunch at the cuff.