Mister Domestic

Determining Yarn Weights

Mister Domestic
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Duration:   4  mins

Yarn comes in different thicknesses or yarn weights. In this video, Mister Domestic shares tips for determining the weight of a yarn. He explores how to determine the wraps per inch for a yarn. With this information, the weight of the yarn will be known.


There are eight standard yarn weights. They are:

  • Lace
  • Super Fine
  • Fine
  • Light
  • Medium
  • Bulky
  • Super Bulky
  • Jumbo


The wraps per inch of a yarn is determined by wrapping the yarn around a crochet hook and then measuring how many times it wrapped around that hook in a one-inch segment. Mister Domestic demonstrates this with a few different yarns from his yarn stash. He is using a US Size N/10mm hook. However, any size hook can be used – you can even use this technique with a knitting needle or pencil. Because you are wrapping the yarn around to measure an inch along the hook, the hook size actually doesn’t matter. The wraps per inch is calculated based on an inch along the length of the hook, so the width of the hook is irrelevant.

Wraps per inch and gauge are important tools for determining yarn weight and can help you figure out what type of yarn you have, even if the yarn label is missing.

Get the Wraps Per Inch Cheat Sheet PDF here.

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5 Responses to “Determining Yarn Weights”

  1. Megan Duguid

    Thank ever so much, Matthew! Living outside of the USA, our yarns do not declare themselves 'weighted' according to the USA system. When working with any USA pattern, I have always read or listened closely to the needle/hook size so as to obtain the about-correct yarn weight. Your tips and the delightful CheatSheet is greatly appreciated. Again, thank you!

  2. Rose King

    Can someone explain to me how this works? Surely the diameter of the rod must play a part and where does the information come from for the number of wraps per inch? Only 6 yarn weights? What about the dedicated crochet yarns, no 3, no 5, no 10 or no 12?

    • Customer Service

      Hi Rose. The video explains how it works. The diameter of the rod has no effect on WPI because WPI measures width of the yarn not length, and the rod diameter only affects length. There are 7 weights on that chart not six, because the chart starts with zero. The Craft Yarn Council of America sets the standards. The only info CYCA lists that is not on the provided chart is 7 Jumbo which clocks in at 1 - 4 WPI. Thread weights are not included in the CYCA standards. Thanks Mary Beth Creative Crochet Corner

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