Yarn weight reference with common US, UK, and Australian names, knitting gauge guidelines, and a swatch-first label comparison.
This is a reference and label comparison, not a guarantee of yarn compatibility. Categories, regional names, and yardage per gram cannot predict your gauge. Swatch with the actual yarn, follow your pattern, and check the finished fabric before substituting.
Compare the eight Craft Yarn Council yarn weight categories, knitting gauge guidelines, and suggested needle and hook sizes. Common US, UK, and Australian names are approximate references. Use the substitution checker to compare labels, then verify your choice with a swatch.
Why You Need a Yarn Weight Reference Chart
A pattern calls for DK while a yarn label says 8-ply. Those names are commonly associated, but they do not prove that the yarn will meet the pattern's gauge. This chart helps you interpret labels before making a swatch.
Compare the category, suggested tool size, fiber content, and label length and weight. Regional names can vary between manufacturers, so treat the UK and Australian columns as approximate naming references rather than exact equivalence rules.
What Are Yarn Weight Categories?
The CYC system groups yarns into eight categories, from 0 (Lace) through 7 (Jumbo). Its chart gives separate knitting and crochet gauge guidelines plus suggested needle and hook sizes.
For example, category 3 includes DK and light worsted. CYC's knitting guideline is 21–24 stockinette stitches per 4 inches on 3.75–4.5 mm needles. This is a reference range, not a prediction for a particular yarn or knitter.
A category is a starting point for selection. Yarn construction, the stitch pattern, the tools, and your tension all affect the fabric. A swatch is needed to assess whether a substitution meets the pattern's requirements.
How Yarn Weight Is Determined
A practical method for estimating yarn weight is the wraps-per-inch test. Wrap yarn around a consistent tool without stretching or overlapping, then count the wraps across one inch. The Craft Yarn Council publishes overlapping WPI guideline ranges and warns that results can vary by how tightly the yarn is wrapped.
Because adjacent WPI ranges overlap, one measurement can point to more than one possible category. Use WPI as a starting point, then make a gauge swatch with the intended needles or hook and follow the pattern or yarn manufacturer's guidance.
This chart shows category and tool-size references; it does not measure or identify an unlabeled yarn. The substitution checker compares the categories you select and optional label yardage, without calculating a compatibility percentage.
Yarn Weight and Substitution Guide
How to Identify Yarn Weights
Yarn Weight Comparison and Substitution Results
Select a category number for notes. Regional names are approximate; use the yarn label and a swatch to check a substitution.
CYC knitting gauge guidelines: stockinette stitches per 4 inches. These are not crochet gauge ranges. Follow your pattern, especially for lace and openwork.
#
US Name
UK Name
AU Ply
Needles
Hooks
Knitting gauge
Lace
Lace / Cobweb
1–2 ply
1.5–2.25 mm US 000–1
Steel 1.4–1.6 mm; regular 2.25 mm US Steel 6, 7, 8; regular B/1
33–40 st
Fingering / Sock
4-ply
3–4 ply
2.25–3.25 mm US 1–3
2.25–3.5 mm US B/1–E/4
27–32 st
Sport / Baby
5-ply
5 ply
3.25–3.75 mm US 3–5
3.5–4.5 mm US E/4–7
23–26 st
DK / Light Worsted
DK
8 ply
3.75–4.5 mm US 5–7
4.5–5.5 mm US 7–I/9
21–24 st
Worsted / Aran
Aran
10 ply
4.5–5.5 mm US 7–9
5.5–6.5 mm US I/9–K/10½
16–20 st
Bulky / Chunky
Chunky
12 ply
5.5–8 mm US 9–11
6.5–9 mm US K/10½–M/13
12–15 st
Super Bulky
Super Chunky
14+ ply
8–12.75 mm US 11–17
9–15 mm US M/13–Q
7–11 st
Jumbo
Jumbo
–
12.75 mm and larger US 17 and larger
15 mm and larger US Q and larger
6 or fewer st
Source: Craft Yarn Council yarn weight guidelines. Steel and regular lace hooks use different sizing systems. US hook labels vary by manufacturer; check the metric diameter.
💡 Substitution Tips
Yards per gram compares label length and weight, not gauge. Matching values do not prove that yarns are interchangeable.
Fiber content matters. Swapping cotton for wool changes drape, stretch, and warmth even at the same weight.
Always swatch with your substitute yarn. Even yarns in the same weight category can knit up differently.
Check the actual yarn label for fiber content and care instructions before buying or substituting.
Ready to evaluate your substitute yarn? Make a swatch, then use the Gauge Calculator to compare its stitch and row gauge with your pattern.
How to Use the Yarn Weight & Substitution Guide
Search by a category number or common name, then select a category number for additional naming notes. Read the knitting gauge and needle or hook guidance alongside the actual yarn label and pattern.
In the substitution checker, select the pattern yarn's category and the proposed substitute's category. You may also enter yards per gram from both labels. Divide total yards by grams and use the same unit for both yarns; do not mix meters per gram with yards per gram.
Understanding Your Results
Same category, adjacent categories, and different categories describe only the selected labels. Every result requires a swatch. Matching categories or yards per gram do not establish matching gauge, thickness, or drape.
The checker cannot determine a needle-size change from the labels. Swatch in the pattern's stitch pattern, follow the yarn's care instructions, then compare stitch gauge, row gauge, and the fabric. Even when gauge matches, consider whether the feel and drape suit the project.
Pro Tips
✓Use length per gram only to compare label information. Similar values do not prove that two yarns will make the same fabric.
✓For colorwork, test the intended stitch pattern and assess elasticity, stitch definition, and drape with the actual substitute yarn.
✓For lace and openwork, follow the pattern's gauge and suggested tools rather than assuming the compact stockinette range applies.
✓Check yarn quantity using the label and a representative swatch. Equal skein weights do not necessarily contain equal lengths.
How to Read This Chart
Each row shows a CYC category, common regional names, and needle and hook guidelines. The gauge column is knitting only: stockinette stitches per 4 inches. Crochet gauge ranges differ and are listed separately in the linked CYC source. Jumbo sizes have no fixed upper limit, and lace hooks distinguish steel from regular hooks. Regional ply names are approximate, not exact conversions or counts of the yarn's strands.
Industry Standards
The Craft Yarn Council publishes categories 0 through 7 as yarn weight guidelines. The recommended gauges and tool sizes are reference ranges, not requirements for every project. Lace and openwork may use larger tools than the chart suggests. CYC also states that the categories do not establish whether two yarns are interchangeable; follow the pattern's gauge and evaluate a swatch.
Real-World Variations
Two yarns with the same category or yardage per gram can differ in fiber content, construction, elasticity, and drape. Even a matching stitch gauge does not guarantee matching row gauge or fabric. Check both labels, swatch in the intended stitch pattern, and assess the fabric after the care process recommended for the yarn. Use the metric tool diameter when a manufacturer's US size designation differs.
The Craft Yarn Council lists 0 (Lace), 1 (Super Fine), 2 (Fine), 3 (Light), 4 (Medium), 5 (Bulky), 6 (Super Bulky), and 7 (Jumbo). Its gauge and tool-size ranges are guidelines, not guarantees for a particular yarn or project.
What is DK weight yarn?
DK, or double knitting, is included in CYC category 3 (Light). The knitting guideline is 21–24 stockinette stitches per 4 inches on 3.75–4.5 mm needles (US 5–7). Australian 8-ply is a common approximate name; verify the actual label and swatch.
Can I substitute DK for worsted weight?
Possibly, but the labels alone cannot answer that. DK and worsted are in adjacent CYC categories. Swatch with the actual yarn in the pattern's stitch pattern and check stitch gauge, row gauge, and fabric. The checker does not calculate compatibility scores or a required needle-size change.
What does ply mean in yarn?
Ply can mean the strands twisted together, while names such as 4-ply or 8-ply also serve as regional weight labels. Those labels are approximate and do not necessarily describe the actual strand count or establish an exact CYC category.
What’s the difference between UK and US yarn terms?
Names such as fingering, 4-ply, DK, worsted, and aran are used differently across markets and manufacturers. The chart gives common approximate associations, not exact conversions. Compare label guidance and swatch before substituting.
How do I find the weight of unlabeled yarn?
Wraps per inch can suggest possible categories, but CYC's ranges overlap and wrapping tension affects the result. Wrap without stretching or overlapping, compare the guidance, then verify with a swatch. A WPI measurement alone cannot confirm a substitution.
Can I substitute any yarn for another?
Matching categories or yards per gram does not establish interchangeability. Swatch in the intended stitch pattern, follow the yarn's care instructions, and compare gauge and fabric with the pattern's requirements. Even matching gauge does not guarantee the same feel or drape.
What happens if I use a different fiber?
Fiber content and yarn construction can change elasticity, drape, texture, and care requirements. Check the actual yarn labels and evaluate a washed and dried swatch according to their care instructions instead of assuming all yarns of one fiber behave alike.
How do I adjust my pattern for a yarn substitution?
Start with the pattern's suggested tools and make a swatch in its stitch pattern. Compare stitch and row gauge and decide whether the fabric suits the project. Try another tool size or yarn and swatch again if needed; matching gauge alone is not enough. Recheck yarn quantity using label information and measured swatch use.
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Keep your place while you work
Use the FiberTools stitch counter for rows, rounds, repeats, and local project notes.