Wraps Per Inch (WPI) Tool Kit

  • $9.99

This clever tool and Knit-Kard lets you measure the thickness of any yarn to determine the weight - perfect for leftover bits and mystery skeins lurking in your yarn stash! This wooden tool has a laser etched legend on it so that you can wrap your yarn around and then count the number of yarn wraps within the 1" marking. Using the handy WPI Knit Kard (which is only available when you buy this tool), you can determine the weight of your yarn based on the WPI (wraps per inch).

Our innovative design gives you the most accurate way of measuring yarn thickness: by turning the tool to gently warp yarn around it, the thickness of the yarn is preserved. We have sold many tens-of-thousands of this tool since its inception in early 2000. Visit the WPI webpage for more info.

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  • Is there any way this tool can be used to measure length needed for long tail cast ons? I use long tail cast ons a lot, and it's very hard to determine the amount needed for casting on large amounts of cast ons. It would be great if this tool could do that, too.

    You need our Long Tail Cast-on Knit Kard which solves the problem. It is included in our popular Knit-Kard set of 14 Knit-Kards. Check it out in our store under Knit Kards.

    I do not believe there is a way to have the WPI Tool calculate this measurement