Wraps Per Inch

WPI: If it sounds like so much crochet alphabet soup to you, don't worry. I didn't know what wraps per inch (wpi) meant until a couple of years ago. Now I figure wpi for all of the yarns used in the Interweave Crochet patterns. Along with the characteristics of a specific fiber, wpi is an invaluable tool when you find you need to substitute a yarn. WPI is simply the number of times you can wrap the yarn around an object in an inch.

 WPI 1You can either use a wpi tool or a ruler. You want to measure the number of times you wrap the yarn around your wpi tool or an inch of the ruler.   If your yarn strand variegates between chunky sections and thin sections be aware that this may not be an entirely accurate way to measure the yarn. Remember when you are wrapping the yarn to wrap it firmly, but don't pull too tightly. Also don't squish as many wraps as you can possibly squeeze and pry into that inch.



 WPI 2  
 WPI 3


You are measuring the width of the yarn strands. Now take your wpi information to your LYS or personal stash. Now pick a yarn that you would like to use. Using the same technique, measure your chosen yarn's wpi. If both wpi measurements closely match, the substitute yarn should give you a correct gauge.




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Toni Rexroat

About Toni Rexroat

Toni Rexroat is the Online Editor of Crochet Me. Outfitted with several crochet hooks and surrounded by bins of yarn, she has been the assistant editor for Interweave Crochet magazine as well as PieceWork, Interweave Crochet’s sister magazine. She was born and raised in a little town in Wyoming where she was exposed to wool and other fibers at an early age, and began crocheting in her early teens. Enjoying a wide variety of fibery hobbies from crochet and knitting to sewing, she is determined to learn to spin so she can crochet with her own yarn.

One thought on “Wraps Per Inch

  1. Toni, I have a wonderful book by Doris Chan but I want to make the sweater with a lighter yarn ie. worster to sports or baby). Do you have any tips for adjusting a pattern for a lighter weight yarn?