Complete Guide to Yarn Weight and Sizes

As a beginner, yarn weights and sizes can go right over your head, and rightfully so! At the start of your crafting journey, whether you knit or crochet, you are focused on your knitting needles and crochet hooks that you don't think of the craft essential- yarn. But yarn shapes up your project, so you must understand it. The terms can sometimes seem confusing and overwhelming, but it is necessary to transform your crafting experiences. Understanding yarn weights can significantly impact your project's size, texture, and appearance. Whether you knit or crochet, yarn weight and size will help determine the suitable size of knitting needles or crochet hooks. To help you understand and get a clear picture, we'll cover all the must-knows of yarn weight and sizes in this blog.

What is Yarn Weight?

The term yarn weight is not actually the weight of the yarn but refers to the thickness of the yarn strand. Categorized by a numbering system ranging from 0 to 7, with 0 being the thinnest yarn weight and 7 being the thickest. The weight is determined by measuring the wraps per inch (WPI)—the higher the WPI, the finer the yarn, and the lower the WPI, the thicker the yarn. Don't worry; we'll break down WPI further to make it easier to understand.

Why is Yarn Weight Important?

Understanding the concept of yarn weight is crucial for several reasons. It helps you select the suitable yarn for your project. For instance, socks would require a fingering weight yarn like Terra, while a cozy baby blanket would be better suited for a worsted-weight merino yarn like Bella. While sweaters, cardigans, hats, and shawls are an ideal fit with Viva. Moreover, knowing the weight is essential because if, at the last minute, you can't find the exact yarn specified in a pattern, you can use yarn in the same weight category to achieve similar results.

How to Check Yarn Weight?

When you get yarn from the store, the skein comes with a label that mentions the weight and other essential details. Most labels indicate the yarn's weight category or a specific number (0-7). The easiest way to know about yarn weight is to check the label. However, if you have leftover yarn without a label, you can use the wraps per inch (WPI) method to identify the weight.

What is the WPI Method?

It is a popular method of understanding yarn weight, but you can do your own calculations or use a standard chart.

  1. Take a small length of yarn (4-5 inches). Ensure it is untwisted and relaxed.
  2. Now, wrap the yarn around a ruler tightly without overlapping strands.
  3. Count the Wraps within one inch.
  4. Match your WPI count to a yarn weight chart to find the corresponding category.

Yarn Weight Chart

A yarn weight conversion chart is helpful for crafters, summarizing the different yarn weights, their thickness, recommended hook or needle sizes, and an estimated ply. Here is a simple chart to help you out:

Yarn Weight (Category)

Thickness (WPI)

0 - Lace


1 - Super Fine


2 - Fine


3 - Light


4 - Medium


5 - Bulky


6 - Super Bulky


7 - Jumbo


Using this yarn weight chart, determine the appropriate yarn for your project and ensure you achieve the desired results.

Most Common Yarn Weight Categories

Fingering Weight Yarn

Fingering weight yarn, also known as sock yarn, is commonly used for lightweight garments like socks, shawls, and other accessories. Terra yarn shines in this category, as it's made from premium-quality Merino wool and polyamide—an ideal blend for durable knits.

DK Weight Yarn

DK (double knitting) yarn is perfect for creating lightweight and breathable fabrics. It's often used for sweaters, cardigans, shawls, hats, scarves, and baby items. DK yarn is a popular choice for beginners due to its ease of handling. Symfonie Yarns' Viva and Luna ranges come in DK weight, offering pure Merino blends in exciting, colorful yarn.

Worsted-Weight Yarn

Tilting towards the slightly bulky yarn weights, worsted-weight yarn is quick-to-make, especially for snuggly projects. A general favorite for warm projects, blankets and home decor, this one is a perfect choice for beginners. Bella, our latest launch in exciting colors and variegated hues, is an absolute favorite.

Extra Fine Merino Wool - Bella

What is Gauge?

Gauge is the number of stitches and rows per inch or a standardized measurement provided on the yarn label. Paying attention to gauge ensures your finished project matches the intended size and appearance. Not getting gauge mentioned in a pattern can lead to a project turning out much smaller or larger than expected, and it's always a bummer when a project doesn't turn out how we envisioned it.

To sum up, knowing how to choose and measure your yarn ensures your projects turn out perfectly and your hard work pays off. So, keep this guide handy to help you navigate the wonderful world of yarn.

Step into yarn crafting with Symfonie Yarns. The hand-dyed yarns are a vision of artists and dyers who understand and are wise in the art of colors and dyeing. Explore the range of Viva, Bella, Luna, and Terra!