Sometimes you come across some yarn that you don’t have any information on. Maybe it’s homespun, maybe the ball band or label got lost. It’s lovely yarn, and you’re dying to start knitting with it. But how do you know what sort of project to pick for it? What size needles to use? Luckily, you don’t have to just guess. There’s actually a very easy trick to figure out yarn weight using nothing more than a ruler.
I was recently swatching with a bit of homespun so had to figure out the weight of it. As I whipped out my ruler I remembered the first time I came across a situation like this. It took me a while to figure out how to deal with it, so I thought I’d share the trick here as it might be of some use to someone!
As I said above, all you need is a ruler (and your yarn, of course). You simply wrap your yarn loosely around the ruler (no stretching!) for a couple of inches: I usually wrap for about three inches. You could do only one, but doing a few more reduces the margin of error by a good bit.
Then count the number of strands lying on your ruler in three inches. Divide by three. This number is the ‘wraps per inch’ (wpi).
That’s remarkably easy, isn’t it?
Of course, there’s a margin for error. And there’s an overlap between different yarn weights and wpi, but yarn weights in commercial yarns can vary wildly within the same category anyway. A lot depends on production methods and type of fibre, for example. Measuring the wraps per inch will give you a pretty good indication of what weight your yarn is.
I hope this helps someone!