How to make kids' pants

1. Materials & tools

Materials (130 cm size)

• Fabric (light to medium cotton, linen, double gauze, etc.) — 110 cm (44 in) wide × about 75 cm (30 in) for 130 cm; about 60 cm (24 in) for 100 cm, about 210 cm (83 in) for adult M
• Flat elastic 2 cm (3/4 in) wide — the child's waist measurement (cut to about 90% of it)

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 “Kids' clothes” → “Kids' pants” from the tabs at the top.
2. Enter the size
   Enter hip, rise, inseam, ease, front crotch extension and waist turn-down, or start from a 80–130 cm or adult M preset. The guide length for the waist elastic appears below the pattern. Set the seam allowance to 1 cm (3/8 in); these steps assume it.
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
   Lay the grainline parallel to the selvage and trace the cut line and seam line. The front and back are different pieces: the back has a deeper crotch curve and sits higher at the center waist.
2. Cut
   Cut 2 fronts and 2 backs as mirror images (fold the fabric right sides together and cut both layers at once and they mirror automatically).
3. Mark the notches
   Snip about 3 mm (1/8 in) into the allowance at the side and inseam notches and at the crotch point. They line the front and back up when you sew.
4. Finish the edges
   Zigzag or serge the allowances on the sides, inseams and crotch curves. The waist and hems are hidden in double folds, so they don't need it.

4. Sewing

4-1. Sew the crotch seams

1. Place the two fronts right sides together and sew the crotch seam from the waist to the crotch point with a 1 cm (3/8 in) seam. Along the curve, sew a second row just outside the first — this is where the seam takes the strain when you sit.
2. Sew the two backs the same way. Zigzag the allowances together, and press the front and back allowances in opposite directions so the crossing point isn't bulky.

4-2. Sew the side seams

1. Place the front and back right sides together and pin with the side notches matched.
2. Sew both side seams from the waist to the hem with a 1 cm (3/8 in) seam, then press the allowances open or toward the back.

4-3. Sew the inseam

1. Pin the inseams, matching the notches and the point where the front and back crotch seams cross.
2. Sew from one hem, through the crotch point, to the other hem in one continuous seam. Go over the area around the crotch point twice to reinforce it.

4-4. Hem the legs

1. Turn the hem allowance under 1 cm (3/8 in), then fold the rest up to make a double fold, and press. (The corners of the hem allowance on the pattern are shaped to lie flat against the side and inseam once folded.)
2. Stitch close to the fold, about 2 mm (1/16 in) in, all the way round, starting from the inseam.

4-5. Thread the waist elastic

1. Turn the waist allowance under 1 cm (3/8 in), then fold it down by the “Waist turn-down” width on the pattern to make a double fold. Stitch round, leaving an opening near center back a little wider than the elastic.
2. Cut the elastic to the guide length shown below the pattern (about 90% of your waist) and thread it through. Try it on to settle the length, overlap the ends by about the elastic's width and stitch them, then sew the opening closed.

✏️ The back crotch curve is deeper and longer than the front. Mix them up and the back will dip when you sit. Writing “front” and “back” on the pieces as you cut saves confusion.

5. Tips & variations

• Grow with them: you can swap the elastic through the opening — shorten it if it gets loose, lengthen it if it gets tight.
• Make it long: add 2–3 cm (1 in) to the inseam and roll the hems up; let them down as they grow.
• Matching set: make a kids' T-shirt from the same fabric for a cute set.