Yarn Calculator

Find out how many balls or skeins of yarn a knitting or crochet project needs. Use the pattern's total yardage, or weigh a swatch to estimate yardage for your own design, then convert between yarns with different lengths per skein.

Two ways to estimate yarn

If you are following a pattern, it lists the total yardage (or metres) for each size. The first calculator converts that into skeins of the yarn you actually bought, because your yarn may have a different length per skein from the one the designer used. Always compare by length, not by weight: 100 grams of a cotton DK and 100 grams of a wool DK can differ by more than 50 yards.

If you are designing your own piece or changing its size, knit or crochet a swatch in your stitch pattern, weigh it, and let the second calculator scale it up. Fabric of the same stitch, yarn and tension uses yarn in proportion to its area, so a blanket ten times the area of your swatch will weigh about ten times as much.

The formulas

1. Skeins = pattern yardage × (1 + margin) ÷ yards per skein, rounded up.
2. Metres to yards: multiply by 1.0936; yards to metres: multiply by 0.9144.
3. Swatch method: project weight = project area ÷ swatch area × swatch weight.
4. Project yardage = project weight ÷ grams per skein × yards per skein.

A margin of 10% covers swatching, gauge differences and weaving in ends. Use 15–20% for projects with lots of colour changes, fringe or where running short would be hard to fix, such as a sweater yarn that might be discontinued.

Yarn weight categories

The Craft Yarn Council's standard numbers yarn thickness from 0 to 7. Labels often show the symbol along with a suggested needle or hook size and gauge.

Rough yardage for common projects

These ranges are only for early planning, before you have a pattern or swatch. Yardage varies widely with size, stitch pattern and gauge — cables and textured stitches can use a third more yarn than stocking stitch, and crochet generally uses more than knitting for the same area.

Worked example

A sweater pattern calls for 1,200 yards of worsted in your size. Your chosen yarn has 220 yards per 100 g skein. With a 10% margin you need 1,320 yards, which is 1,320 ÷ 220 = 6.0 skeins, so buy six — or seven if the margin feels tight for a yarn you cannot easily re-buy. For a blanket you design yourself, a 6 × 6 inch swatch weighing 11 g scales to a 40 × 50 inch blanket (2,000 square inches) as 2,000 ÷ 36 × 11 ≈ 611 g, about 1,344 yards of the same yarn: seven skeins plus a margin.

Dye lots and substitutions

Buy all your yarn from the same dye lot, printed on the label, because colour can shift slightly between batches. When substituting a yarn, match the weight category and, more importantly, the gauge in the pattern: knit a swatch and check you get the stated stitches and rows per 4 inches. A yarn with similar yards per gram is usually a similar thickness; fibre also matters, as cotton and linen have more drape and less stretch than wool.

Measuring yarn you already have

For leftover or unlabelled yarn, weigh it and use the yards per gram of a known sample: wrap a measured length — say 10 yards — and weigh it on a precise scale, then scale up. A yarn swift and a ball winder with a counter make the job faster. Knowing the yardage of your stash stops you starting a project you cannot finish.

Crochet versus knitting

For the same yarn and area, crochet fabric generally uses more yarn than knitted stocking stitch, because crochet stitches are taller and more layered; many crocheters plan for roughly a quarter to a third more. Dense stitches such as single crochet or moss stitch use more than open lace or mesh. That is why the swatch method is so useful: it measures your own stitch, tension and hook size rather than a general rule, and it works equally well for knitting, crochet and even woven or macramé projects.