How much fabric do I need? Calculator

Two free tools. Convert the yardage printed on your pattern to the width of the fabric you actually found, or estimate yardage from your pattern pieces when the pattern gives none. Results in yards and meters. Nothing you type leaves this page.

Units

Yards and inches Meters and cm

Convert your pattern's yardage to another fabric width

Fabric the pattern asks for In yards, e.g. 2 1/4 Width on the pattern In inches, e.g. 45 Width of your fabric In inches, e.g. 60 Safety margin Percent, for layout waste

Convert

Estimate from your pattern pieces

Measure each piece at its widest and longest, seam allowance included, the way it lies on the grain. For a piece cut on the fold, enter the width of the pattern piece itself (half the cut piece) and tick On fold.

Fabric width In inches Selvage trim Both edges together, in inches Shrinkage Percent, if you prewash

Piece	Width	Length	Cut	On fold

Add a piece Try an example Clear the pieces

Estimate fabric

Your pattern always wins. The yardage printed on a pattern comes from a real layout of its pieces for each size and width. These tools are estimates for when your fabric is a different width, or the pattern gives no yardage. When in doubt, buy a little more.

How this is calculated

Converting to another width

The same garment needs the same area of fabric, so a wider fabric needs less length:

your length = pattern length × pattern width ÷ your width × (1 + margin)

Example: the pattern asks for 2 1/4 yd of 45 in fabric and yours is 60 in. 2.25 × 45 ÷ 60 = 1.69 yd. Plus the 10 percent margin, 1.86 yd, rounded up to 1 7/8 yd. The margin covers what the area formula cannot see: pieces do not tile perfectly, and a wide piece may waste the strip beside it. Results always round up, to the next eighth of a yard or 10 cm. If your fabric is narrower than the pattern's, check that the widest pieces still fit across it.

Estimating from pieces

1. Usable width is the fabric width minus the selvage trim.
2. A piece cut on the fold lies open at twice its pattern width. A piece cut 2 counts as two pieces.
3. Pieces stay on the grain, so they are never turned sideways.
4. The pieces are laid out longest first, in rows across the fabric. Each piece goes on the first row with room for it. If none has room, it starts a new row as long as itself. This is a standard packing method called first fit decreasing height.
5. The fabric length is the rows added together. With shrinkage, the pieces are laid out on the washed width and the length is scaled back up: length ÷ (1 − shrinkage).

Each piece is treated as the rectangle around it, and real curved pieces nest into each other better than rectangles do. So this usually asks for a little more than a careful layout would, which is the safe direction.

Not included: matching a print, directional prints and nap. For those, add one full repeat and lay every piece the same way.

Try the layout on your own fabric

With Sttchr you can lay your pattern pieces right on the fabric you have before you cut. The app shows the pattern on the fabric at true size through your iPhone or iPad camera, so you can see whether everything fits, then trace. See how the sewing pattern tracer works, or read how to trace a pattern onto fabric. Still choosing a size? Start with the sewing pattern size calculator.

Questions

How do I convert fabric yardage to a different width?

Multiply the yardage on the pattern by the pattern's fabric width, divide by your fabric's width, then add about 10 percent for layout waste. Round up to the next eighth of a yard or 10 cm.

How much extra fabric should I buy?

Add the shrinkage if you prewash, since cotton and linen often shrink 3 to 5 percent. Add one full repeat for a print that has to match, and a little more for directional prints or nap, where every piece has to face the same way.

Is the yardage on my pattern more accurate than a calculator?

Yes. The yardage on a pattern comes from a real layout of its pieces. Use this calculator when your fabric is a different width, or when the pattern gives no yardage at all.