Wraps per inch - how to find out the ply of your yarn
- Emily
- Sep 11
- 2 min read
Updated: Oct 20
Like so many knitters and crocheters, I have a stashes of yarn squirrelled away in boxes and bags in multiples corners of the house. Inevitably, labels get damaged or lost and then you end up with a pile of yarn and no idea what ply it is.
Ply is the term used to describe the thickness of the yarn, which can be very thin such as cobweb/lace weight, all the way up to super bulky thick yarn.
As well as mystery balls of yarn from previous shopping trips, I also buy jumpers and knitwear from charity shops to unravel and reuse the yarn. Again after unravelling, it's hard to tell what ply the yarn is.
An easy way to find out what ply your yarn is, is the wraps per inch technique or WPI.
And all you need is a ruler.
All you need to do is wrap your yarn around the ruler for 1 inch or 2.5cm and count how many wraps are within that inch or centimetres.
This number then gives you a rough idea of which ply your yarn is.
Below is a list of different yarns and their WPI numbers. The higher the number, the finer the ply.
Lace/2ply - 30-40+
Sock/3 ply - 18-30
4 ply - 14-18
DK - 11-15
Aran - 8-10
Chunky - 6-8
Super Chunky - 1-4
In the first photo, the green cotton yarn was from a jumper I bought from a charity shop. The wraps per inch numbered 17, so it's 4 ply.
In the second photo, the yarn is noticeably thicker. It's WPI was 11, so is at the thicker end of DK (Double Knit).
You can watch my short video on how to find out the ply of your yarn using WIP on my TikTok and YouTube accounts by clicking on the links below
To work out how many yards or metres your yarn is, check out my blog post about it here
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