Wraps Per Inch: Why Does it Matter?

Yellow and Blue Crochet Cable Cowl

You may think we are nuts, but Wraps Per Inch (WPI) really matter when it comes to choosing yarn for your next project whether it is knitting or crochet. Before I make your head spin (or "get into the details"), lets take a look at these two samples of the Campfire Cowl - both cowls are made with yarn classified as DK weight, but as you can see the finished measurements are quite different!

This variation in size occurs because the WPI count for each weight of yarn is not a single number, but a range of numbers. The yarn used in the blue sample has a WPI of 12 and the yarn used in the yellow sample has a WPI of 14. The yarn used for both samples is technically DK weight, but they fall on opposite ends of the range and result in the sizing differences. What makes selecting yarn based on the weight unreliable, is that yarn industry leaders lack consistency of the listed WPI range for each weight! The labeling of yarn as worsted or sport weight is typically correct because yarn falls within one of the ranges provided for WPI. Because the actual WPI can vary within each weight you will want to pay close attention to the WPIs listed for the yarn used in the pattern you want to create.

How do you find this information?

All of our patterns include the WPI information to make the pattern as pictured (of course gauge is still important so make sure you swatch!). If you are working on a pattern from someone else, often you can find the WPI information listed on Ravelry or the manufacture's website. Using this information you can compare the WPI of the yarn in the pattern to the yarn you want to use. If it is not listed there you can also use a WPI Tool to verify that the yarn you have selected matches the yarn used in the sample. 

Measuring WPI as a part of your creative process is another tool to help ensure that the project you create is just as you'd like for it to be - beautiful!