Thursday, January 14, 2021

How to Determine Yarn WPI (wraps per inch)


When working on a crochet project, it is very important to use the appropriate yarn size, because it greatly influences the final result. Yarn size, or yarn weight tells us how thick the yarn actually is.  

But sometimes, the label does not suggest the size/weight, or you acquire yarn without a label, and then it is important to know the thickness as to determine the right size. During all these past years of crocheting, I can recognize sizes just by looking and feeling the yarn, but it has sporadically happened to me, to not being  quite able to determine the size when it comes to chunkier yarns, especially sizes 5 and 6.

The solution for this is immensely easy. 

To determine the size of yarn or the Wraps Per Inch (WPI) you need yarn (of course), a ruler (or tape measure) and an ordinary HB pencil. 


Start wrapping the yarn around the pencil until the wraps measure an inch. That is how you determine the size. Above you have the table that shows how many wraps per sizes. 

Here it is important to know that when wrapping, the wraps must not overlap, there shouldn't be any gaps, and also the tension must not be too strong.

 I hope you find this useful. Happy crochet time!


Alhana said...

Thanks for the explanation! I have always wondered about this and it turned out easier to understand than expected. By the way, did you know we do something similar to know if a thread is adequate for a certain pricking in bobbin lace? ;-)

Maya Kuzman said...

Well, I didn't know that, but now that you've mentioned it, it sounds logical and expected :)
I know that weavers and knitters do that as well.

handmade by amalia said...

I've not heard of this - very useful!!! Thanks for sharing.

ruşyena said...

Useful knowledge. Thanks dear Maya.
And happy crocheting!

Kate said...

Thank you for sharing this.

My thrift store addiction said...

How helpful! Thanks for sharing at Vintage Charm!