How to make a belt bag (waist pack)

1. Materials & tools

Materials (standard size)

• Main fabric (nylon, canvas or heavy cotton) — about 70 × 60 cm (28 × 24 in)
• Lining fabric (light cotton) — the same amount
• Fusible interfacing — for the main fabric
• Webbing or a self-fabric belt — the length you chose
• A side-release buckle and slider — 1 each
• Snap or magnetic fastener — 1 set

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 “Bags” → “Belt bag (waist pack)” from the tabs at the top.
2. Enter the size
   Enter the finished width, height, gusset, flap depth, belt length and cut width. Presets cover small, standard and a sling-style version.
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 body (base on the fold), the flap and the belt.
2. Cut
   Cut the body in main and lining, the flap in main and lining, and one belt.
3. Apply interfacing
   Fuse interfacing to the main fabric so the bag keeps its shape when it is not full.

4. Sewing

4-1. Make the flap and belt

1. Sew the flap main and lining right sides together, leaving the attachment edge open. Clip the corner curves, turn, press and topstitch.
2. For a self-fabric belt, fold in quarters and topstitch. For webbing, cut and seal the ends.

4-2. Sew the sides and gusset

1. Fold the main body at the base, right sides together, and sew both sides. Do the same with the lining, leaving a 10 cm (4 in) gap.
2. Pinch each base corner into a triangle and sew across at the gusset depth. Check both sides match.

4-3. Attach the flap and belt

1. Turn the main bag out and slip it inside the lining, right sides together.
2. Catch the flap at the back edge and the belt ends at the sides as you sew around the opening.
3. Check the belt is not twisted before you sew.

4-4. Finish

1. Turn through the gap in the lining, close it, push the lining in and topstitch around the opening.
2. Thread the buckle and slider onto the belt.
3. Load the bag, close the flap and fit the snap or magnetic fastener.

✏️ The belt attachment is the highest-stress point on this bag. Backstitch two or three times, or stitch a rectangle with a cross. Webbing itself is strong; the stitching holding it is what fails, and when it does the bag goes on the ground.

5. Tips & variations

• Belt length changes the bag: about 100 cm (39 in) for the waist, about 140 cm (55 in) to wear across the body. A slider covers both.
• Magnetic fastener: opens one-handed while walking, which is exactly how this bag gets used.
• Water-repellent fabric: it is an outdoor bag, so a sudden shower should not matter.