Wraps per Inch aka WPI

When you think you have a medium worsted weight yarn but you actually have a sport weight yarn, you can end up with a product that is a very different size than you thought. Look at the feature picture so you can see what I mean. Both of the yarns I bought were labeled as worsted weight but when I tested them, it turned out that the yellow (10 WPI) was worsted and the blue was a sport weight (13 WPI) yarn.

Wraps per inch, is a technique used to figure out the weight of yarn. Like if you have scarp yarn with no label, this system gives you the ability to know the weight with a very simple procedure.

The bad news is that I did not find consistency with the numbers on the chart worldwide. Sometimes the difference between one chart and the other was huge. However, I did find that this was mostly true when I researched organizations or companies. Most of the people making the tools used for this technique were consistent with their numbers. That made me very happy and excited about sharing with you what I’d learned.

The Procedure

.The method is very simple. You can use a tool you buy, a pencil, a ruler, or a cut-out.

If you are a Patreon patron, you can download the cheat sheet with a tool template on the Patreon site.

PATRONS: CLICK HERE

Wrap the tool loosely with the yarn until you have 1 inch of surface covered.
Count the number of wraps in that 1 inch of surface.
Check the chart for the weight of your yarn based on wraps.

Note that I included the Craft Yarn Council numbers just to show the huge difference between an organization and the numbers used by tool makers. I don’t know the reason for the huge difference. I do believe I once heard someone say that the tools are mostly used by people who sell their own brand of yarn. The tool helps them stay within the industry standards.

If you know why there is this difference please share the information in the comment section. I have listed three sources below. You can take a look at the information yourself. Just click the red words.