How many skeins of yarn you need for a knitting or crochet pattern

Yarn calculator: pattern yardage divided by skein yardage

The skeins to buy are the yards the pattern needs divided by the yards in one skein, rounded up, plus one spare skein. Always work in yards (or meters), never in skeins or grams: two yarns of the same weight can hold very different lengths, and Lion Brand points out that cotton is heavier than wool, so a cotton skein of the same weight has fewer yards.

A pattern can state the yarn in three ways, and the calculator takes all of them:

• in yards or meters: the simplest case, the yardage is used as it is;
• in skeins of another yarn: skeins × yards per skein of that yarn, from its label;
• in ounces or grams of another yarn: weight × yards per ounce of that yarn. A 3.5 oz skein with 220 yd gives about 63 yd per ounce.

The result is always rounded up. Lion Brand's example is 800 yards with 85-yard skeins, 9.4 skeins, which becomes 10; then it suggests buying one more, and its dye lot article says the same. So the spare starts at 1 skein and you can change it. If you hold two strands together, the yardage doubles: set the number of strands in the advanced options.

The count holds only if your gauge swatch matches the pattern gauge. With a different yarn, knit or crochet a swatch first.

A worked example

A US pattern calls for 1,100 yd and you want skeins of 3.5 oz = 200 yd, with one spare. These are the values the calculator opens with in US units.

• Skeins for the pattern: 1,100 ÷ 200 = 5.5, so 6 skeins.
• With the spare: 6 + 1 = 7 skeins, that is 1,400 yd and 24.5 oz of yarn.
• You use 100 yd of the sixth skein. At the end 300 yd are left: the other half of the sixth skein plus the spare.

In the UK, with balls labelled in meters: a pattern needs 900 m and you buy 50 g balls of 125 m. 900 ÷ 125 = 7.2, so 8 balls, 9 with the spare, 1,125 m and 450 g. If the pattern says "10 balls of 100 m", that is 1,000 m: exactly 8 balls of 125 m, 9 with the spare. The same 900 m pattern worked with two strands needs 1,800 m: 14.4, so 15 balls, 16 with the spare.

Yarn weights: the Craft Yarn Council categories

Before you swap yarns, check that the new one is the same weight as the pattern yarn. The Craft Yarn Council sorts yarns into categories 0 to 7, and labels that follow its standard show the category number. These are the guideline values from its chart, in stockinette over 4 in:

Category	Yarn types	Stitches per 4 in	Needles
0 Lace	fingering, 10-count thread	33-40	US 000-1 (1.5-2.25 mm)
1 Super Fine	sock, fingering, baby	27-32	US 1-3 (2.25-3.25 mm)
2 Fine	sport, baby	23-26	US 3-5 (3.25-3.75 mm)
3 Light	DK, light worsted	21-24	US 5-7 (3.75-4.5 mm)
4 Medium	worsted, afghan, aran	16-20	US 7-9 (4.5-5.5 mm)
5 Bulky	chunky, craft, rug	12-15	US 9-11 (5.5-8 mm)
6 Super Bulky	super bulky, roving	7-11	US 11-17 (8-12.75 mm)
7 Jumbo	jumbo, roving	6 or fewer	US 17 and up (12.75 mm and up)

The Craft Yarn Council says these are guidelines only and that two yarns in the same category are not automatically interchangeable. The swatch decides: if the new yarn on the pattern needles gives the same stitches per 4 in, you can use the pattern yardage.

Reading the yarn label

The label gives the weight and the length of one skein: those are the two numbers to enter for the skein you buy. The weight only tells you how much yarn you carry home; the count runs on yards. If the pattern gives the yarn by weight, you also need the weight and length of the original yarn, from the pattern or the yarn's own page.

The label also carries the dye lot number: yarn is dyed in batches and each batch gets its own number. Skeins of the same color from different lots can look different even with the same dyes, and Lion Brand advises buying all the skeins you need from one dye lot at once. That is why the spare is worth buying now: a skein bought later may come from another lot.

Common mistakes

• Counting skeins instead of yards. If the pattern asks for 10 balls of 100 m and your yarn comes in 125 m balls, 8 plus the spare are enough, not 10.
• Substituting by weight. 400 g of a yarn with 100 m per 50 g is 800 m; in a yarn with 125 m per 50 g the same 800 m weigh 320 g.
• Rounding down. With 5.5 skeins you need 6: with 5 you run out before the end.
• Buying the spare later. A skein from another dye lot can show on the finished piece.
• Skipping the swatch. A yarn in the same category can knit up looser or tighter: the piece changes size and the yardage no longer fits.