Crochet Yarn Calculator

Crochet vs knitting yarn usage

Crochet typically uses 25–30% more yarn than knitting for the same finished dimensions. This is because crochet stitches are taller and use more yarn per stitch than comparable knitting stitches. This is an important consideration when substituting yarn between knitting and crochet patterns.

Yarn weight categories

Yarn weight determines how thick the yarn is and directly affects how much length is on each skein (thicker yarn = fewer meters per 100g):

• Lace / Fingering (weight 0–1): Very thin. 400–800 m per 100g.
• Sport / DK (weight 2–3): Light. 240–300 m per 100g.
• Worsted / Aran (weight 4): Medium, most common. 180 m per 100g.
• Bulky (weight 5): Thick. Around 110 m per 100g.
• Super Bulky (weight 6): Very thick. Around 60 m per 100g.

Those are the Craft Yarn Council numbers, and the yarn weight converter works from the same table, so a figure from one page converts correctly on the other. Note that Super Bulky is CYC 6, not 7. Seven is Jumbo, the arm-knitting stuff, which this calculator does not cover. This page used to number them one too high all the way up.

Project yarn requirements (approximate)

These estimates are for average gauge and standard project sizes. Always buy 10–15% extra as a safety buffer. Dye lots vary between skeins, and running out mid-project means you may not find an exact colour match.

• Baby blanket (90 × 90 cm): about 760 m worsted; 585 m bulky
• Throw blanket (120 × 150 cm): about 1,865 m worsted; 1,436 m bulky
• Scarf (180 cm long): about 325 m worsted
• Beanie hat (adult): about 145 m worsted; 112 m bulky
• Sweater (adult M): about 1,515 m worsted
• Amigurumi (medium, 15 cm): about 80 m worsted

Every one of those is the knitted figure plus 27.5%, taken from the shared worsted baselines on the knitting yarn calculator. They used to be hand-set and drifted in both directions: the sweater was 24% under what a crocheted medium takes and the baby blanket was 32% over.

Metres change a lot, weight changes too

Here is the thing that surprises people the first time they substitute yarn, and this page had it backwards until recently. Switch a baby blanket from worsted to super bulky and the length collapses, from about 760 metres to 420. The old version of this page said the weight would stay put at around 555 grams either way, on the reasoning that the blanket is the same size in the same fibre, so it must hold the same wool.

It does not work out that way. Published per-size yardage puts a medium sweater at 1,900 yards in fingering and 1,300 in worsted, a ratio of 1.46 rather than the 2.2 you get by dividing the metres-per-100g figures. Push those through the grams and the fingering sweater weighs about 475 g while the bulky one weighs 769 g. A thicker yarn worked at its own proper gauge makes a thicker, denser cloth. The blanket is the same size but it is not the same fabric, and a chunky one really is heavier to pick up.

So both numbers move when you substitute, which is why the calculator gives you metres, grams and the ball count rather than asking you to convert between them. Grams are still the number to take to the shop, because that is what a ball is sold by, but you cannot work them out from the metres without knowing which weight you chose.

Buy the whole lot at once

Yarn is sold in 50 g and 100 g balls, and the dye lot number is printed on the band. Two balls of the same shade from different lots can be visibly different, and it shows most on exactly the large flat expanses where you would use several balls. Buy all of them together, check the lot numbers match, and keep one band so you can search for the lot if you do run short.

Swatch before you start

Crochet a 10 × 10 cm swatch with your chosen yarn and hook before committing. If your stitch count comes out 10% off the pattern’s gauge, your yarn requirement is off by roughly the same amount, and on a blanket that is a whole ball.