Tina-blog-templateQuestion: For my latest project I found a lovely top to knit. The pattern recommended using a DK wool and acrylic blend, but I decided to knit it with a DK cotton instead. The tension was the same, so it seemed like an easy enough switch to make. But as I was knitting my top, I found I needed more yarn than the pattern had suggested. Why should this be?

Tina Egleton answers your knitting questions.

Answer: When substituting one yarn for another, it’s important to remember that yarns are balled according to weight.

As cotton is heavier than a wool-acrylic mix, there’ll be fewer metres of it per ball. And that’s what has happened in this case.

Fewer metres per ball means less yarn to knit with, and the yarn’s been used up more quickly by the pattern.

There are many reasons why you might want to use a different yarn from the one specified. You might have found a pattern you like and the yarn for it isn’t available any more.

Maybe you want to make a garment more appropriate for a particular season, or perhaps you’re hoping to use up a few balls you have spare.

To help you work out how much of a substituted yarn you’ll need for your project, we’ve got a simple guide that you can follow. Sometimes, getting your knitting right comes down to a bit of number crunching!