Knitting Yarn Calculator

Yarn quantity estimation starts from the project and its size, then adjusts for how thick the yarn is. Thick yarn covers the same area in far less length, which is why a pattern’s yardage is meaningless until you know what weight it was written for.

Yardage by project (worsted weight, medium size)

Adjusting for yarn weight

Everything above is worsted. To move to another weight, multiply:

Notice that the two columns nearly cancel. A worsted sweater is about 1,000 yards and needs roughly 525 g of yarn; the same sweater in super bulky is about 350 yards and still needs around 500 g. The garment is the same size and made of the same fibre, so it weighs about the same however thick the yarn is. Grams tell you what to buy; yards only make sense within one weight.

Balls needed

Balls = Total yards ÷ yards per ball, rounded up

Yards per ball is printed on the label and varies enormously, so it is an input above rather than an assumption. Round up, always, and buy from a single dye lot.

Knitting versus crochet

Crochet uses roughly 25–30% more yarn than knitting for the same finished piece, because crochet stitches are taller and each one consumes more yarn. If you are converting a pattern between the two, the crochet yarn calculator carries the same projects with that adjustment already applied.

Two things that shift these numbers

Gauge. These figures assume you hit the pattern’s stated gauge. Knit tighter and you pack more stitches into the same area, using more yarn; knit looser and you use less. A gauge off by 10% moves the yarn requirement by about the same amount, which on a blanket is a whole ball.

Stitch pattern. Cables pull the fabric in and eat 20–35% more yarn than plain stockinette. Stranded colorwork carries both yarns across every row, so budget 20–30% extra. Lace goes the other way: all those yarn-overs make fabric out of holes, so it runs 5–15% under.