Fabric yardage calculator

List the rectangles you need to cut, set the fabric width, and get the yardage to buy with a layout showing where each piece goes. Pattern repeats, one-way prints and shrinkage are all accounted for.

Fabric to buy

2 1/8 yd

The layout uses 73 in of 42 in usable width, 75.2 in after allowing 3% shrinkage. Rounded up to the next 1/8 yard: 2 1/8 yd (2.125 yd), or 2.0 m if sold by the metre. Pieces cover 89% of the fabric used.

Selvedges left and right, fabric length running down the page. ↻ marks a piece turned 90°.

How it works

Fabric comes off the bolt at a fixed width and whatever length you ask for, so the problem is to fit the pieces across the width and use as little length as possible. The calculator tries several layouts and keeps the shortest:

Rows. Pieces are sorted longest first and placed side by side across the width; a new row starts when the next piece will not fit beside the others. Each row is as long as its longest piece. This is tried with pieces as entered, and, unless the fabric is one-way, with pieces turned so their long or short side runs across.
Free packing. With no repeat to match, pieces do not have to sit in rows, so a guillotine packer (the same one as the sheet cut optimizer) also tries tucking shorter pieces under one another. Every layout it makes can be cut with straight cuts across the fabric.

With a pattern repeat, only row layouts are used, and each row's length is rounded up to a whole number of repeats so that every row starts at the same point in the pattern. Then length × (1 + shrinkage) is converted to yards (÷ 36) and rounded up to the next 1/8 yard, and to metres (× 0.0254) rounded up to the next 10 cm.

Worked example

Two envelope cushion covers and a table runner from quilting cotton with 42" of usable width: two 20 × 20" fronts, four 20 × 13" back panels and one 60 × 15" runner, all cut sizes.

No repeat, not one-way: the runner runs down one side and the cushion pieces pack beside and below it, using 73" of fabric. Adding 3% for shrinkage gives 75.2", or 2.09 yards: buy 2 1/8 yards (2.0 m).
One-way print: no piece may turn, and the layout needs 80", 82.4" with shrinkage: 2 3/8 yards.
With a 13 1/2" repeat to match: the runner's row rounds from 60" to 67 1/2" (five repeats) and each 20" row of cushion pieces rounds to 27" (two repeats). That is 121 1/2", 125.1" with shrinkage: 3 1/2 yards, well over half as much again.

The jump from 2 1/8 to 3 1/2 yards for a patterned fabric is typical, and it is why a shop assistant asks whether you intend to match the pattern.

Fabric widths

Fabric	Sold as	Usable, typically
Quilting cotton	44–45"	about 40–42"
Apparel and home-dec fabrics	54"	about 52"
Knits, linings, many apparel fabrics	58–60"	about 56–58"
Wide quilt backing	108"	about 104–106"

Measure between the selvedges of the actual bolt, leaving out any printed or unprinted edge you would not use. Two inches of difference in width can change the whole layout.

Eighths of a yard

Yards	Inches	Centimetres
1/8 yd	4.5	11.4
1/4 yd	9	22.9
3/8 yd	13.5	34.3
1/2 yd	18	45.7
5/8 yd	22.5	57.1
3/4 yd	27	68.6
7/8 yd	31.5	80.0
1 yd	36	91.4

Where it stops being reliable

Rectangles only. Garment pieces with curves and angles nest into one another in ways rectangles cannot, so enter each piece as its bounding rectangle and treat the result as an upper estimate. For garments, the yardage chart on the commercial pattern envelope is the better source.
Pieces cut on the fold should be entered at their full opened-out width.
Bias-cut pieces lie at 45° to the grain and need a different layout altogether.
Shop cuts are rarely perfectly straight. Many sewists add a few inches to square up the cut end.

Common questions

What does directional or one-way mean?

A print or fabric that looks different upside down or sideways: a one-way print of animals all facing up, corduroy, velvet and other napped fabrics, or anything with a clear stripe you want running one way. Every piece must then lie the same way on the fabric. Tick the box and the calculator never turns a piece, which usually costs extra length.

How do pattern repeats change the yardage?

To match a repeat, each piece has to start at the same point in the pattern, so the fabric used for each row of pieces is rounded up to a whole number of repeats. A 20-inch piece on a fabric with a 13.5-inch repeat really uses 27 inches. This is the same rule curtain makers use when they round each drop up to the next repeat.

Should I include seam allowances?

Yes. Enter the size you will cut, not the finished size. A 20-inch finished cushion front with 1/2-inch seams is cut 21 by 21 inches.

How much will my fabric shrink?

It depends on fibre and weave. Many cottons shrink a few percent in their first wash and linen and rayon can shrink more, while polyester barely shrinks. The honest way to know is to wash and measure a sample. Enter 0 if you will not pre-wash or the fabric is pre-shrunk.

Why is the answer rounded up to an eighth of a yard?

Because that is the smallest cut most North American fabric shops will make. If your shop cuts by the metre or by the inch, use the metre figure or the exact length from the result instead.