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Yarn Weight & Substitution Guide

Knitting & Crochet

Last updated: March 16, 2026

Interactive yarn weight chart with US, UK, and Australian names — plus a substitution compatibility checker.

Yarn substitution recommendations are provided as guidance only. Fiber content, twist, and construction vary between brands. Always swatch to verify gauge before substituting yarns in a pattern.

This interactive chart compares all eight Craft Yarn Council yarn weight categories across US, UK, and Australian naming systems. Use it to identify yarn weights, check substitution compatibility, and find recommended needle and hook sizes for any weight category.

Why You Need a Yarn Weight Reference Chart

A pattern calls for DK weight yarn, but the label on your skein says 8-ply — are they the same thing? Different countries and manufacturers use different naming conventions for yarn thickness, and the confusion can lead to purchasing the wrong weight entirely and producing fabric with incorrect drape and gauge.

Australian and British patterns use ply counts, North American patterns use category names, and European labels often list only recommended needle size in millimeters. A comprehensive reference chart bridges these systems so you can substitute yarns confidently across international patterns.

What Are Yarn Weight Categories?

The Craft Yarn Council established a standardized system of eight weight categories numbered 0 through 7, from lace weight at the finest end to jumbo at the heaviest. Each category defines a range of acceptable gauges, recommended needle or hook sizes, and common project applications.

These categories provide a universal language for yarn thickness. Category 3, called DK or light worsted, is the same as 8-ply in Australian terminology and roughly corresponds to what many European brands label as suitable for 4.0mm needles. The chart maps all these naming systems together.

Within each category there is still variation — a loosely spun DK and a tightly plied DK will behave differently despite sharing a label. The weight category is a starting point for selection, and swatching confirms whether a specific yarn performs as expected for your chosen pattern.

How Yarn Weight Is Determined

The simplest hands-on method for identifying yarn weight is the wraps-per-inch test. Wrap your yarn snugly around a ruler for one inch without stretching or overlapping, then count the number of wraps. Each weight category corresponds to a specific WPI range that has been standardized through decades of textile measurement.

For example, 11 wraps per inch identifies DK weight yarn. DK typically knits at 5.5 to 6 stitches per inch on US 5 through 7 needles, or 3.75 to 4.5mm. Worsted weight shows about 9 wraps per inch, while fingering weight shows 14 or more. The WPI test works even when labels are missing or unreadable.

The calculator cross-references WPI ranges, standard gauge ranges, and recommended needle sizes for all eight CYC categories, giving you multiple ways to confirm your yarn weight classification before committing to a pattern or purchasing additional skeins.

Yarn Weight and Substitution Guide

How to Identify Yarn Weights

Yarn Weight Comparison and Substitution Results

Tap a row to highlight it. Use the substitution tab to check if two specific yarns are compatible.

#US NameUK NameAU PlyNeedlesHooksGauge
0LaceLace / Cobweb1–2 ply1.52.25mm
US 000–1
1.52.25mm
US 6 steel–B
3240 st
1Fingering / Sock4-ply3–4 ply2.253.25mm
US 1–3
2.253.5mm
US B–E
2732 st
2Sport / Baby5-ply5 ply3.253.75mm
US 3–5
3.54.5mm
US E–7
2326 st
3DK / Light WorstedDK8 ply3.754.5mm
US 5–7
4.55.5mm
US 7–I
2124 st
4Worsted / AranAran10 ply4.55.5mm
US 7–9
5.56.5mm
US I–K
1620 st
5Bulky / ChunkyChunky12 ply5.58mm
US 9–11
6.59mm
US K–M/N
1215 st
6Super BulkySuper Chunky14+ ply812mm
US 11–17
916mm
US M/N–Q
711 st
7JumboJumbo1225mm
US 17–50
1525mm
US Q–S+
16 st

💡 Substitution Tips

  • Yards per gram is the most reliable way to compare yarns — more accurate than weight category alone.
  • 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.
  • The same yarn in different colors can have slightly different gauges — dark dyes especially.

How to Use the Yarn Weight & Substitution Guide

Browse the interactive chart to look up any standard yarn weight from lace (0) through jumbo (7). Each weight shows the Craft Yarn Council category number, typical gauge range, recommended needle and hook sizes, and common project types. The chart includes US, UK, and Australian naming conventions — what Americans call worsted, Australians call 10-ply, and the UK calls aran or DK depending on the specific weight.

Use the substitution checker to compare two yarn weights side by side. Enter the yarn weight your pattern calls for and the weight you want to use. The checker tells you whether the substitution is compatible, borderline, or incompatible, and explains what adjustments to make if the substitution is borderline.

Understanding Your Results

A "compatible" result from the substitution checker means the two yarns are in the same thickness range and will produce similar gauge on the same needles. It does not mean the finished fabric will look or feel identical. Fiber content, ply structure, and spin direction all affect drape, stitch definition, and halo. A tightly plied merino worsted and a loosely spun single-ply worsted are the same weight but produce very different fabric.

The "borderline" result means the substitution may work with a needle size adjustment. For example, a heavy DK yarn can sometimes work in place of a light worsted if you go up one needle size. Always swatch with the substitute yarn to confirm before starting the full project.

Pro Tips

From 30+ years of fiber arts experience

  • When substituting yarn, match meters per 100 grams first, then check fiber content. Two yarns with the same m/100g will knit at nearly the same gauge regardless of what category name is on the label.
  • Do not substitute acrylic for wool in stranded colorwork. Acrylic does not felt or bloom, so the floats will not lock together during blocking and the fabric will be loose and sloppy.
  • Lace weight yarns vary wildly within their category. A cobweb-weight lace at 1,300 yards per 100g is not interchangeable with a heavy lace at 800 yards per 100g, even though both are labeled "lace."
  • Sport weight and DK weight overlap significantly. If a pattern calls for DK and you have sport weight, swatch on the recommended needles — it may work without changes.

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