Pattern layout estimator
Measure your pattern pieces, lay them on the fabric width you are buying, and see the cutting layout and the length you need, before you get to the shop.
How to use the layout estimator
Enter the fabric width and choose how you will cut. Folded lengthwise is the usual way for garments: selvedges together, two layers, so one cut gives a left and right pair. Open, single layer suits large pieces, napped fabrics and anything you cut one at a time.
Then describe each pattern piece as a rectangle around it, seam allowances included. Cut is how many fabric pieces you need. Tick On fold when the pattern says “place on fold” and enter the paper piece; on folded fabric it goes against the fold, on open fabric it is cut flat at twice the width. Grain sets how a piece may lie: lengthwise keeps its length along the fabric, either way lets the estimator turn it crosswise when that saves fabric, and bias tilts it 45°.
The estimator places each piece where its top edge ends lowest, tries several orders, keeps the shortest result and draws it to scale with the fold, a ruler and the cut line. Each piece carries its number from your list and a grainline arrow.
Reading the result
Real pieces have curves and nest into each other, so a hand layout is often a little shorter. A bias piece takes its whole tilted square, which overstates long bias strips; work those out separately. Add something for straightening the cut end and for pre-wash shrinkage. Example: the gathered skirt preset needs 88 in on 45 in fabric (buy 2½ yd) but only 58 in on 60 in fabric, because the waistband and pockets fit beside the skirt pieces.
For a quick figure without measuring pieces, try the garment fabric estimator.
Sources
- Simplicity, How to sew striped fabric: in a “with nap” layout all pieces face the same direction; layouts without nap let pieces turn to save fabric.
- The packing method is a standard skyline heuristic for strip packing: a greedy estimate, not a guaranteed shortest layout.
Questions
How do I measure a pattern piece?
Lay the paper piece flat with its grainline running up and down. Measure the widest point across and the longest point along the grainline, including seam and hem allowances. That rectangle is what to enter.
What does “cut 2” mean on folded fabric?
On fabric folded in two layers, one cut through both layers gives a mirrored pair, so a piece marked cut 2 needs one placement. If you ask for an odd number, the last cut gives one spare, which the cutting list shows.
Why is the layout longer than my pattern envelope says?
The estimator treats every piece as a rectangle, while real pieces have sloping sides and curves that nest together. Envelope layouts also mix folds, for example a partly folded section. Treat the result as a safe upper estimate.
When should I cut on a single layer?
For pieces too wide for folded fabric, for slippery or napped fabrics, and when matching plaids, where cutting one layer at a time lets you line up each piece. Switch the layout to open, single layer to see the length that needs.
Are my pieces saved?
Yes, in this browser's local storage only, so they are still there next time. Nothing is uploaded. Clear all pieces removes them.