Mattress Stitch Calculator — Seaming Yarn Needed

Mattress stitch uses approximately 3 times the seam length for DK weight yarn on stockinette fabric. Heavier yarns use proportionally more, and textured stitches like garter or cables can increase usage by 15-30%. Always cut more than you think you need.

Mattress stitch is an invisible seaming technique where you pick up bars between edge stitches on each piece alternately. When pulled tight, the seam is virtually invisible from the right side and creates a flat join.

For garter stitch, pick up the bottom loop of the garter ridge bump on one side, then the top loop of the corresponding ridge on the other. This creates an invisible join that mimics garter stitch across the seam.

Use the same yarn for invisible seams. If your project yarn is bulky or textured, you can use a smoother yarn in the same colour for easier sewing. For very chunky yarns, split a ply to reduce bulk in the seam.