How to make a raglan t-shirt

1. Materials & tools

Materials (men's M)

• Main fabric (jersey or interlock) — about 150 cm wide × 150 cm (59 × 59 in)
• Optional: contrast knit for the sleeves
• Neckband: on the pattern — cut it from the main fabric
• Ballpoint machine needle and stretch thread

Tools

• Sewing machine (or needle and thread)
• Fabric marker or pencil
• Ruler and scissors
• Iron
• Pins or clips

2. Make the pattern (auto-generated in Katagami)

With the Katagami pattern tool, you just enter the finished size and it drafts a seam-allowance-included pattern, tiled to print at actual size on Letter or A4.

1. Open the tool
   Open the pattern tool and choose “Adult clothes” → “Raglan T-shirt” from the tabs at the top.
2. Enter the size
   Enter bust, length, sleeve length, cuff circumference, neck width and ease. Presets cover women's S/M and men's M/L. With “Add a neckband” on, the pattern includes a neckband 90% of the neckline length.
3. Set the seam allowance
   Use the slider at the bottom (beginners: 1.0–1.5 cm / about 3/8–5/8 in).
4. Print
   Press “Print (actual size)”, then in the print dialog set Scale = 100% and turn “Fit to page” OFF. Check the 50 mm calibration box on the first guide sheet with a ruler.

3. Cutting the fabric

1. Trace the pattern
   Trace the front, back, raglan sleeves and neckband. Mark the notches on the raglan seams — they are what keeps front and back level — and the quarter marks on the neckband.
2. Cut
   Cut one front and one back on the fold, two sleeves and one neckband (long side across the stretch).
3. Finish the edges
   Serge or zigzag the raglan and side allowances.

4. Sewing

4-1. Sew the raglan seams

1. Pin the front edge of one sleeve to the front raglan edge, matching the notches, and sew.
2. Sew the back edge of the same sleeve to the back. Repeat for the other sleeve.
3. All four raglan seams are slightly curved. Match the notches first and the curves fall into place.

4-2. Sides and underarms

1. Sew from the cuff along the underarm and down the side in one continuous line on each side.

4-3. Attach the neckband

1. Sew the short ends of the neckband together to make a loop, press the seam open and fold the band in half lengthwise.
2. Put the band seam at center back. Match its quarter marks to the neckline divided into four (center front, center back and the two points halfway between) and pin.
3. The band is 10% shorter than the neckline, so stretch it slightly as you sew it all the way around.

4-4. Cuffs and hem

1. Turn the cuffs (2 cm / 3/4 in allowance) and hem (2.5 cm / 1 in) up once by the pattern allowance and stitch with a zigzag or stretch stitch.

✏️ The four raglan seams are the whole garment, so the notches matter more here than anywhere else. Pin notch to notch first, then fill in between — starting at one end guarantees you run out of fabric at the other. Before attaching the neckband, stretch the loop over your head to check it fits.

5. Tips & variations

• Contrast sleeves: the classic baseball tee. It costs nothing extra and transforms the look.
• Easier than a set-in sleeve: no easing, no sleeve cap. If set-in sleeves have put you off, start here.
• Ribbing instead: the neckband can be cut from ribbing too, using the same pattern piece.
• Three-quarter sleeves: a shorter sleeve length gives the classic raglan proportions.