How much yarn or fabric do you need for a project?

Divide 800 by the meters on the ball band and round up: 210 m balls → 4 skeins (840 m total). With 200 m balls you need 4 as well; with 400 m cakes, only 2. Always check the dye lot — buy all skeins at once for the same lot number.

10% is the minimum for simple cuts; 15% for stripes, plaids or directional prints that need pattern matching; 20% for beginners or slippery fabrics. Shrinkage before cutting can eat another 5% on cotton — pre-wash if the bolt label says to.

On the pattern header, Ravelry project page, or designer website — usually listed per size (S/M/L). Pick your size row, not the average. If only grams are given, convert using the yarn’s meters-per-50g on the band.

Width affects how pattern pieces fit, not the price formula directly — you pay per running meter along the bolt. A wider bolt may let you use less length for the same garment, which is why patterns specify width. This calculator uses the length your layout requires plus waste.