Yarn Weight Categories Explained

Yarn weight categories are a way to categorize different types of yarn based on their thickness or weight. This categorization is useful for a variety of purposes, including selecting appropriate yarn for a project, calculating yardage needed, and substituting one yarn for another.

Yarn weight categories

There are several different yarn weight categories, which are typically designated by a number or a name. The most commonly used yarn weight categories are as follows:

Lace:

 This is the thinnest yarn weight category, often used for delicate shawls or doilies. Lace yarn typically has a gauge of 33-40 stitches per 4 inches (10 cm) using size 0-3 (2-3.25 mm) needles.

Fingering or sock:

 This is a very fine yarn weight, often used for socks or light, airy shawls. Fingering yarn typically has a gauge of 27-32 stitches per 4 inches (10 cm) using size 1-3 (2.25-3.25 mm) needles.

Sport or baby:

 This is a lightweight yarn often used for baby items or lightweight garments. Sport yarn typically has a gauge of 23-26 stitches per 4 inches (10 cm) using size 3-5 (3.25-3.75 mm) needles.

Worsted or aran:

 This is a medium-weight yarn that is suitable for a wide variety of projects, including garments, blankets, and accessories. Worsted yarn typically has a gauge of 16-20 stitches per 4 inches (10 cm) using size 7-9 (4.5-5.5 mm) needles.

Bulky or chunky:

 This is a heavier weight yarn that is often used for warm, cozy blankets and winter accessories. Bulky yarn typically has a gauge of 12-15 stitches per 4 inches (10 cm) using size 9-11 (5.5-8 mm) needles.

Super bulky or jumbo:

 This is the thickest yarn weight category, often used for quick, chunky projects like blankets or scarves. Super bulky yarn typically has a gauge of 7-11 stitches per 4 inches (10 cm) using size 13-19 (9-16 mm) needles.

When working with a pattern, it is important to choose a yarn weight that matches the recommended gauge, so that the finished project will have the correct size and drape. If a different weight of yarn is used, it will be necessary to adjust the pattern by changing the needle size or the number of stitches cast on.

In addition to the standard yarn weight categories, there are also conversion charts available that can help you convert between different systems of yarn weight classification, such as the UK and US systems. These conversion charts typically list the different yarn weights in each system, along with their corresponding gauge and recommended needle size, making it easier to substitute one type of yarn for another.

What Does Yarn Weight Mean?

Yarn weight refers to the thickness or weight of a particular yarn. Yarns can vary in thickness from very thin and delicate (lace weight) to very thick and bulky (super bulky or jumbo weight). The weight of a yarn affects its properties, such as the drape of a finished fabric, the amount of warmth it provides, and the amount of yardage needed for a project.

Yarn weight is typically categorized by a number or a name, such as lace, fingering, sport, worsted, bulky, or super bulky. These categories are based on the recommended gauge, or number of stitches per inch, for a particular yarn weight, which in turn determines the appropriate needle size to use. The gauge and needle size are important factors to consider when choosing a yarn weight for a particular project, as using a yarn that is too thick or too thin can result in a finished project that is too large or too small.

Yarn weight is an important consideration for any knitting or crochet project, as it can greatly affect the final outcome of the project. Understanding yarn weight categories and how to choose the appropriate yarn for a project is key to creating a finished piece that looks and feels just right.

Why Does It Matter?

Yarn weight matters for several reasons when it comes to knitting or crocheting a project. Here are a few reasons why yarn weight is important:

Gauge:

 Each yarn weight category has a recommended gauge, or number of stitches per inch, which can vary greatly between categories. The recommended gauge is important because it helps ensure that the finished project will turn out the right size and shape. Using a yarn that is too thin or too thick for the recommended gauge can result in a finished project that is too small or too large.

Yardage:

 Yarn weight can also impact the amount of yarn needed for a project. A thinner yarn will typically require more yardage than a thicker yarn to complete the same project. This is because the thinner yarn will need more stitches to cover the same area as a thicker yarn.

Drape:

 The thickness of the yarn can affect the drape, or how the finished project hangs or drapes on the body. A thin yarn may create a delicate and flowing fabric, while a thicker yarn may create a more structured or bulky fabric.

Texture:

 The thickness of the yarn can also impact the texture of the finished project. A thin yarn can create a fine, intricate texture, while a thicker yarn can create a bolder, more pronounced texture.

Overall, understanding yarn weight and choosing the appropriate yarn for a project is key to creating a finished piece that looks and feels just right. It can help ensure that the project turns out the right size and shape, has the desired drape and texture, and uses the right amount of yarn.

What Is WPI?

WPI stands for “wraps per inch,” which is a way of measuring the thickness of a yarn. It is a simple and useful method of determining the weight of an unlabeled or handspun yarn.

To measure WPI, you wrap the yarn around a ruler or a WPI tool, which is a small device designed specifically for this purpose. You count the number of wraps that fit within a 1-inch (2.5 cm) section, and this number corresponds to the yarn weight category. For example, a yarn that measures 16 wraps per inch would be considered a worsted weight yarn.

Measuring WPI is particularly useful for handspun or unlabeled yarns, which may not have a weight category listed on the label. By measuring the WPI, you can determine the weight of the yarn and select an appropriate pattern or needle size for your project. It can also be helpful for determining the weight of yarns that have been separated from their original label or have had their label removed.

Measuring WPI is not as precise as using a gauge swatch or a yardage meter, but it can provide a rough estimate of the yarn weight and help you make informed decisions when choosing a pattern or selecting needles.

What Does Ply Mean?

In the context of yarn, ply refers to the number of strands that are twisted together to make a single strand of yarn. When you look at a yarn closely, you may notice that it is made up of multiple smaller strands twisted together. The number of these smaller strands, or plies, determines the yarn’s ply.

For example, a single-ply yarn is made up of a single strand of yarn, while a two-ply yarn is made up of two strands twisted together. A four-ply yarn is made up of four strands twisted together, and so on.

The number of plies can affect the thickness, strength, and texture of a yarn. Generally speaking, a single-ply yarn will be softer and more delicate than a plied yarn of the same thickness. However, a plied yarn will be stronger and more durable than a single-ply yarn of the same thickness.

The ply of a yarn can also impact the stitch definition and texture of a finished project. A plied yarn can create more defined stitches and a crisper texture, while a single-ply yarn can create a more subtle, blended texture.

It’s important to note that the number of plies is not always an indicator of the yarn weight or thickness. For example, a lace weight yarn can be single-ply, two-ply, or more, while a bulky weight yarn may be single-ply or four-ply. The yarn weight is determined by the thickness of the individual strands and the recommended gauge, rather than the number of plies.

Yarn Weight Types and Categories

There are several yarn weight types and categories that are commonly used in the knitting and crochet world. Here is a breakdown of the most common yarn weight categories, along with their recommended gauge and needle size:

Lace weight: 

The thinnest yarn weight category, often used for delicate shawls and other lace projects. Recommended gauge: 8+ stitches per inch. Recommended needle size: 000-1 (1.5-2.25 mm).

Fingering weight:

 Slightly thicker than lace weight, often used for socks and lightweight garments. Recommended gauge: 7-8 stitches per inch. Recommended needle size: 1-3 (2.25-3.25 mm).

Sport weight:

 A versatile yarn weight that can be used for a range of projects, including lightweight sweaters and blankets. Recommended gauge: 6 stitches per inch. Recommended needle size: 3-5 (3.25-3.75 mm).

Worsted weight:

 A popular yarn weight for a wide range of projects, including sweaters, hats, and scarves. Recommended gauge: 5 stitches per inch. Recommended needle size: 7-9 (4.5-5.5 mm).

Aran weight:

 A heavier yarn weight that can be used for warm, cozy garments and accessories. Recommended gauge: 4-5 stitches per inch. Recommended needle size: 8-10 (5-6 mm).

Bulky weight:

 A very thick yarn weight that is often used for quick projects, such as hats and scarves. Recommended gauge: 3-4 stitches per inch. Recommended needle size: 10-11 (6-8 mm).

Super bulky weight:

 The thickest yarn weight category, often used for chunky blankets and other home decor projects. Recommended gauge: 1-2 stitches per inch. Recommended needle size: 13+ (9+ mm).

It’s important to note that yarn weights can vary slightly between different brands and manufacturers. Always check the recommended gauge and needle size on the yarn label before starting a project, and make a gauge swatch to ensure that your finished project turns out the right size and shape.

UK, Australia, and New Zealand Yarn Weights and Standards

In the UK, Australia, and New Zealand, yarn weight categories are often referred to by a numbering system that corresponds to the thickness of the yarn. Here is a breakdown of the most common yarn weight categories in these regions, along with their corresponding number and recommended needle size:

Lace weight:

 This category is sometimes referred to as 2-ply or 3-ply yarn. Recommended needle size: 1.25-2.75 mm.

4-ply (fingering weight)

This category is sometimes referred to as sock yarn or baby yarn. Recommended needle size: 2.75-3.25 mm.

Double knitting (DK):

 This category is sometimes referred to as 8-ply yarn. Recommended needle size: 3.25-4 mm.

Aran: 

This category is sometimes referred to as 10-ply yarn. Recommended needle size: 4.5-5.5 mm.

Chunky: This category is sometimes referred to as 12-ply or bulky yarn. Recommended needle size: 5.5-8 mm.

It’s important to note that while the numbering system used in the UK, Australia, and New Zealand is similar, the recommended needle sizes can vary slightly between regions and yarn manufacturers. It’s always a good idea to check the recommended gauge and needle size on the yarn label and make a gauge swatch to ensure that your finished project turns out the right size and shape.

Yarn Weight Conversion and Comparison

Converting yarn weight between different systems can be a bit tricky, as there is no exact equivalent for each category. However, there are some general guidelines that can help you make conversions and comparisons between yarn weights.

One helpful tool for comparing yarn weights is the WPI (wraps per inch) method. To use this method, you simply wrap the yarn around a ruler or other measuring tool, counting the number of times it wraps around in one inch. This gives you the WPI of the yarn, which you can compare to the WPI of other yarns to get a general sense of their relative thickness.

Here are some rough conversions between common yarn weight categories in the US, UK, Australia, and New Zealand systems, along with their corresponding WPI:

UK Yarn Type	US Yarn Types	Australian Yarn Ply	Suggested Hook in Metric Size Range	Suggested Hook in US Size Range
1 ply	Lace	2 ply	1.5 – 2.25 mm	Steel 8-1 Regular Hook B1
2 ply	Fingering	3 ply	2.25 – 3.5 mm	B1 – E4
4 ply	Sport	5 ply	3.5 – 4.5 mm	E4 – 7
DK	DK	8 ply	4.5 – 5.5 mm	7 – I9
Aran	Worsted	10 Ply	5.5 – 6.5 mm	I9 – K10 ½
Chunky	Bulky	12 Ply	6.5 – 9 mm	K10 ½ – M/N13
Super Chunky	Super Bulky	Over 12 ply	9 – 15 mm	M/N13 – Q
Jumbo	Ultra /Roving	Over 20 Ply	15mm and larger	Q and larger

It’s important to note that these conversions are only approximate, and that the recommended gauge and needle size can vary between different yarns and manufacturers. Always check the recommended gauge and needle size on the yarn label and make a gauge swatch to ensure that your finished project turns out the right size and shape.

Comparing Yarn Weights by Yards/Meters

While the WPI method is a useful tool for comparing yarn weights, another way to compare them is by yards/meters per gram or ounce. This measurement takes into account the thickness of the yarn as well as its density, making it a more precise way to compare yarns.

To compare yarn weights by yards/meters per gram or ounce, you’ll need to do a bit of math. Here’s how:

Weigh a small sample of the yarn, such as 10 grams or 0.5 ounces, on a digital kitchen scale.

Measure the length of the sample in yards or meters. You can do this by wrapping the yarn around a ruler or measuring tape, counting the number of wraps, and then multiplying by the length of each wrap.

Divide the total length of the sample by its weight in grams or ounces. This gives you the yards/meters per gram or ounce of the yarn.

For example, if your 10-gram sample of yarn measures 25 yards, you would divide 25 by 10 to get 2.5 yards per gram. You can use this measurement to compare the yarn to other yarns with known yards/meters per gram or ounce.

Here are some rough guidelines for yarn weights based on their yards/meters per gram or ounce:

• Lace weight: 400 yards/meters or more per 50 grams or 1.75 ounces
• Fingering weight: 250-400 yards/meters per 50 grams or 1.75 ounces
• Sport weight: 150-250 yards/meters per 50 grams or 1.75 ounces
• Worsted weight: 100-150 yards/meters per 50 grams or 1.75 ounces
• Bulky weight: 50-100 yards/meters per 50 grams or 1.75 ounces
• Super bulky weight: 50 yards/meters or less per 50 grams or 1.75 ounces

Again, it’s important to note that these guidelines are approximate, and that the recommended gauge and needle size can vary between different yarns and manufacturers. Always check the recommended gauge and needle size on the yarn label and make a gauge swatch to ensure that your finished project turns out the right size and shape.

How to Calculate Yarn Weight Using WPI

Calculating yarn weight using WPI (wraps per inch) is a simple process that involves counting the number of times a yarn wraps around a ruler or other measuring tool in one inch. Here’s how to do it:

Cut a length of yarn that is at least 6 inches long.

Hold one end of the yarn against the ruler, and wrap the yarn around the ruler until it covers one inch.

Count the number of times the yarn wraps around the ruler in one inch. This is the WPI of the yarn.

Use the following chart to determine the weight category of the yarn based on its WPI:

Weight Category	WPI
Lace (0)	30-40+
Super Fine (1)	14-30
Fine (2)	12-18
Light (3)	11-15
Medium (4)	9-12
Bulky (5)	6-9
Super Bulky (6)	5-6
Jumbo (7)	1-4

Keep in mind that the weight category of a yarn is just one factor to consider when choosing yarn for a project. You should also pay attention to the fiber content, gauge, and recommended needle size, as these can all affect the look and feel of your finished project.

Yarn Weight Conversion Chart

Here’s a yarn weight conversion chart that shows how yarn weight categories from different countries and systems compare to each other:

UK Yarn Type	US Yarn Types	Australian Yarn Ply	Suggested Hook in Metric Size Range	Suggested Hook in US Size Range
1 ply	Lace	2 ply	1.5 – 2.25 mm	Steel 8-1 Regular Hook B1
2 ply	Fingering	3 ply	2.25 – 3.5 mm	B1 – E4
4 ply	Sport	5 ply	3.5 – 4.5 mm	E4 – 7
DK	DK	8 ply	4.5 – 5.5 mm	7 – I9
Aran	Worsted	10 Ply	5.5 – 6.5 mm	I9 – K10 ½
Chunky	Bulky	12 Ply	6.5 – 9 mm	K10 ½ – M/N13
Super Chunky	Super Bulky	Over 12 ply	9 – 15 mm	M/N13 – Q
Jumbo	Ultra /Roving	Over 20 Ply	15mm and larger	Q and larger

Note that while these weight categories may have similar names across different countries, there can still be variations in actual thickness, fiber content, and recommended gauge and needle size between different yarns. Always check the yarn label for recommended gauge and needle size, and make a gauge swatch to ensure that your finished project turns out the right size and shape.