How yarn substitution works

This calculator compares grams per meter for the suggested yarn and your replacement yarn. A close result can be a useful first check, but fiber, twist, loft and gauge still matter. Always make a swatch before buying yarn for a large project.

What to compare before substituting yarn

Check yarn weight category, meters per 100 grams, fiber content, recommended gauge, care instructions and the fabric you want. A cotton yarn and a wool yarn with similar numbers can still feel very different.

Frequently asked questions

Is the same yarn weight enough?

No. Weight categories are ranges. Compare length-to-weight ratio and gauge as well.

How many substitute skeins should I buy?

The calculator estimates the required number from total pattern length and the replacement skein length, then rounds up to a full skein.