Yarn comes in different thicknesses or yarn weights. In this video, Corrina Ferguson shares tips for determining the weight of a yarn. She looks at both the wraps per inch (WPI) as well as the gauge to determine the thickness of the yarn.
YARN WEIGHTS
There are eight standard yarn weights. They are:
• Lace
• Super Fine
• Fine
• Light
• Medium
• Bulky
• Super Bulky
• Jumbo
Corrina focuses on the seven most common yarn weights in the video.
WRAPS PER INCH (WPI)
The wraps per inch of a yarn is determined by wrapping the yarn around a knitting needle and then measuring how many times it wrapped around the needle in a one-inch segment. Corrina demonstrates this with a super bulky yarn and a worsted weight yarn.
GAUGE
The gauge of a yarn is also an important tool for figuring out the weight of a yarn. A small swatch can be worked in Stockinette stitch (knit on Right Side/purl on Wrong Side) and the stitches can be counted to determine the gauge. Corrina demonstrates this on a worsted weight swatch. She counts the stitches over a two-inch segment, which allows her to calculate the stitches per inch.
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.
Six or fewer (not six or less)
What size needle do you use to figure out WPI? In the demo it looks like you are using a big needle.
Hello Pamela,
Thank you for contacting us.
The needle size does not matter, you could even use a ruler or piece of cardboard to wrap the yarn. A larger needle just makes it easier to count those wraps. What you are looking for are how many wraps sit next to each other in an inch. The video goes into how to get an accurate count.
If you have any other questions, please chat, email, or call Customer Service. 
Sincerely,
Sarah
The Knitting Circle Video Membership
Very Very Interesting & Knowledgeable. Thank You 🧶
what size needle were you using? It looks like 10 or more?
Hi Jackie. US Size 15 (10.0mm) needle is used in the video. Because you are wrapping the yarn around to measure an inch along the needle, the needle size actually doesn’t matter. The wraps per inch is calculated based on an inch along the length of the needle, so the width of the needle is irrelevant. You can use any size needle (or even a pencil) to measure the wraps per inch. I don’t recommend using a really small needle (like a US 2 or smaller), only because the wraps might move around too easily and stack on top of each other.
Jen
The Knitting Circle
I wrapped a fingering yarn on a size 4 needle and had 25 wraps. Same yarn on a size 13 needle had 19 wraps. Your response regarding needle size doesn’t matter is not entirely accurate, although the result does seem to fall in the same general yarn size range.
What size needle are you using to determine the wpi?
Hi Kathryn,
US Size 15 (10.0mm) needle is used in the video. Because you are wrapping the yarn around to measure an inch along the needle, the needle size actually doesn’t matter. You can use any size needle (or even a pencil) to measure the wraps per inch.
Let us know if any other questions come up!
Sincerely,
Codi
The Knitting Circle Video Membership
I was wondering the same thing about the needle size. Thanks for the additional information. No need to respond.
I found the video very helpful. Thank you. I would like to suggest though that it be explained in the video about the sizing question. It would have been easier for everyone if it had been explained at the beginning that it didn’t matter what size the object the yarn was wrapped around. I don’t think you would of had to explain it so many times. I came to the discussion because I had the same question as everyone else. Thanks again for the video.
Hi Lynne. Thank you for your feedback. I will forward your comments on to the proper department. We do appreciate your feedback.
Jean
The Knitting Circle Video Membership
Does it matter what size needle you wrap the yarn around.
Hi Sandra,
Here is what our expert had to say:
US Size 15 (10.0mm) needle is used in the video. Because you are wrapping the yarn around to measure an inch along the needle, the needle size actually doesn’t matter. You can use any size needle (or even a pencil) to measure the wraps per inch.
Let us know if any other questions come up!
Sincerely,
Codi
The Knitting Circle Video Membership
What size needle are you using to wrap thread around. Larger needle less wraps around smaller more
Hi Susan,
Here is what our expert had to say:
US Size 15 (10.0mm) needle is used in the video. Because you are wrapping the yarn around to measure an inch along the needle, the needle size actually doesn’t matter. You can use any size needle (or even a pencil) to measure the wraps per inch.
Let us know if other questions come up!
Sincerely,
Codi
The Knitting Circle Video Membership
It is so annoying to have to ask the same question over and over. What size needle is used for the demonstration. I know I could use a pencil. I want to know what size knitting needle was used. Simple.
Hey Barbara
Here’s what the experts had to say about your question:
It’s a US Size 15 or 10mm knitting needle in the video. But you can use any size knitting needle to measure the wraps per inch!
Please let us know if you have any further questions
Sincerely,
Danesha
The Knitting Circle Video Membership
What size needle should be used when doing the wrap test?
Hi Candy!
Here’s what our expert had to say:
You can use any size needle (or even a pencil!) to measure. Because you are measuring the thickness of the yarn based on the number of times it’s wrapped around the needle, the needle size actually doesn’t matter at all.
Sincerely,
Codi
The Knitting Circle
What size needle do you use for wraps per inch measurement?
Hi Pam. You can really use any needle size – or even a pen or pencil! Because you are measuring the thickness of the yarn, it’s about how much width the yarn will take up on the needle, not the amount/length of yarn that gets wrapped around the needle. Hope that helps!
Thanks
Jen
The Knitting Circle
Yes it did. Thank you
in the video, I may have missed it but Corrina does not tell what size the knitting needle is that she is wrapping. The size of the needle would certainly affect the number of wraps per inch.
Hi Gwendolyn. You can really use any needle size – or even a pen or pencil! Because you are measuring the thickness of the yarn, it’s about how much width the yarn will take up on the needle, not the amount/length of yarn that gets wrapped around the needle. Hope that helps!
Thanks
Jen
The Knitting Circle
Hi Gwendolyn we both thinking the same . I have to get my head around that one . Your not in your own 😀