SeamGrid seam markA folded square with a seam line and grid marks, drawn as a compact textile monogram.SeamGridbrowser-local sewing calculators
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A maker's field guide

Turn finished measurements into a calm cut plan.

SeamGrid helps you draft pouches, skirts, and quilt plans without guesswork. Start with the boxy pouch calculator, or choose the tool that matches your project.

Open boxy pouch calculatorSee how it works
  • Browser-local
  • No account
  • Shown math
A finished boxy pouch on a linen-covered sewing table beside a measuring tape and tailor's chalk.
A boxy pouch beside the measuring tape and chalk used to plan it.

Choose a tool

A four-tool table, organized by job

Two pattern tools and two quilt-planning tools, arranged the way a working table would be: start with the thing you are making, then move to the next question.

Pattern drafting

Pouches and skirts

These tools turn finished sizes into cut dimensions and radii for the two most common measurement-to-pattern jobs.

Boxy pouch pattern calculator

Turn finished pouch measurements into cut dimensions, boxed-corner marks, and a small sewing plan.

Open boxy pouch calculator

Circle-skirt pattern calculator

Enter waist, ease, skirt length, and allowances to see the stitch and cut radii for a full, half, or quarter circle skirt.

Open circle-skirt calculator

Quilt planning

Backings and binding

These tools compare fabric layouts and strip plans so you can cut with a little more certainty before you buy or cut cloth.

Quilt backing calculator

Compare equal-panel lengthwise and crosswise layouts and see which uses the shorter unrounded fabric length.

Open quilt backing calculator

Quilt binding calculator

Plan straight-grain width-of-fabric strips with diagonal joins and see exact unrounded arithmetic.

Open quilt binding calculator

How it works

How SeamGrid works

A small workflow keeps the page useful on mobile: choose the tool, enter the measurements you already know, and read the plan before you cut.

  1. Choose the calculator that matches the project you are holding.

  2. Enter finished measurements, seam allowance, and units.

  3. Read the cut plan, diagram, and limitations before you cut fabric.

Trust

Built for trust, not hype

Your measurements stay in the browser, the formulas stay visible, and the results are framed as planning help rather than a promise of physical validation.

  • Browser-local by default
  • No account or upload
  • Clear assumptions and limits