The yarn weight conversion chart helps you match yarn weights across US, UK, Australian, and international naming systems. Yarn weight names vary significantly by country — what the US calls "worsted" the UK calls "aran." The CYC (Craft Yarn Council) numbering system (0-7) is the most universal standard.
Yarn Weight Conversion Chart
| CYC # | US Name | UK Name | Australian | WPI | Knit Needles | Crochet Hook |
|---|
Identify Yarn Weight by WPI
Wrap yarn around a ruler for 1 inch and count wraps. Enter the number below to identify the yarn weight.
Understanding Yarn Weights
The yarn weight conversion chart is essential for knitters and crocheters working with patterns from different countries. British patterns use completely different weight names than American ones, and Australian yarns have their own naming conventions.
The CYC System
The Craft Yarn Council developed the 0-7 numbering system to create a universal standard. Most modern yarn labels include a CYC symbol with a number in a skein icon. When patterns specify "CYC 4 worsted," any yarn labeled 4/medium/worsted will work — regardless of country of origin.
Working with Unlabeled Yarn
Use the WPI (Wraps Per Inch) method to categorize mystery yarns from stash or thrift stores. Wind the yarn around a ruler for exactly 1 inch — not too tight, not loose — and count the wraps. Match the count to the chart to identify the weight category, then choose the recommended needle/hook size as a starting point.
Frequently Asked Questions
Is this yarn weight conversion chart free?
Yes, completely free with no signup required.
What is CYC yarn weight?
CYC stands for Craft Yarn Council, which created the standard yarn weight numbering system used on most yarn labels. The scale goes from 0 (lace) to 7 (jumbo), with each number representing a weight category. When a pattern specifies a CYC weight number, you can use any yarn in that category.
What does WPI mean in yarn?
WPI stands for Wraps Per Inch. It's a universal measurement of yarn thickness — wind the yarn around a ruler for 1 inch and count the wraps. Lace yarn wraps 18+ times per inch; jumbo/arm knitting yarn wraps 1-3 times. WPI lets you accurately categorize mystery yarns without labels.
What is the most common yarn weight for beginners?
Worsted weight (CYC 4) is the most recommended for beginners. It's thick enough to see your stitches clearly, available everywhere, and works well with both knitting needles and crochet hooks in the common size range (US 7-9 needles, H-J hooks).
What is DK weight yarn?
DK (Double Knitting) is a light-weight yarn (CYC 3) that originated in the UK. It's lighter than worsted but heavier than fingering/sock yarn. DK weight is popular for baby items, lightweight garments, and accessories. US equivalent terms include 'light worsted' or 'double knitting.'
How do I substitute yarn weights in a pattern?
First, identify the CYC weight number of the original yarn and your substitute. Yarns one full step apart (e.g., worsted vs. bulky) require pattern adjustments. The key is matching gauge — knit a swatch and adjust needle/hook size until you match the pattern's specified gauge, even if you have to deviate from recommendations.