Using WPI To Find Out Yarn Weight

Admit it, you have a bunch of yarn in your stash that you wouldn’t be able to identify if your life depended on it! So, it just sits there. If only you could identify the weight, you’d be using it all up! Some of it might have been donated to you without the labels. You might have even thrown away the labels. Or maybe you even purchased it on clearance with a makeshift price tag. But don’t worry! There is a way to find out what the weight is using Wraps Per Inch, or WPI. Using this method can help you get your yarn stash better organized. For more organization tips check out How To: Organize Your Yarn Stash.

How to Find WPI


  • Ruler/Measuring Tape
  • Number Two Pencil
  • Marker
  • Your mystery yarn.

Step 1:

First things first, get out your pen/pencil, your ruler and your marker and begin to mark off 1 inch sections directly onto your pen/pencil.

Step 2:

Begin wrapping your yarn around your pen/pencil while counting each rotation. The trick is to wrap your yarn close enough so that there are no gaps, yet, also far enough away so that there is no over lapping. Continue counting until you have wrapped for a total inch (use marking on your pen/pencil to see where to start and stop counting.) This number will be your WPI.

Step 3:

Now, to find out the weight, refer to the WPI chart below and match your WPI count to yarn weight.

There you go it’s as easy as that!

Hopefully this helps you figure out what some of that mystery yarn in your stash is! The best way to keep all that organized would be getting colored rubber bands! Use each color to signify a different yarn weight that way you’ll never forget what weight it was!


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