When we classify yarn by weight, it has little to do with how heavy a yarn is, but rather how thick the strand of the yarn is. The Craft Yarn Council, along with publishers, fiber and needle and hook manufacturers, have created a series of guidelines and symbols to bring uniformity to yarn, needle, and hook labeling to make it easier to select the right materials for a project and complete it successfully.
Yarn Weight Chart at a Glance
Every standard yarn weight side by side. International knitters: the common ply name (UK / AU / NZ) is shown in brackets — note that "ply" here is a traditional thickness label, not the literal number of strands. WPI (wraps per inch) and approximate length per 100 g are guides for identifying and substituting yarn; both vary with fibre and brand, so always swatch.
| Weight | Names (ply) | Knit needle US (mm) | Crochet hook | Knit gauge / 4" | WPI* | ~m / 100 g* | Best for |
|---|---|---|---|---|---|---|---|
| 0 — Lace | Lace, cobweb (1–2 ply) | 000–1 (1.5–2.25) | Steel 1.4–1.6 / 2.2 mm | 33–40 | 18+ | 600–1000+ | Shawls, wraps, lacework |
| 1 — Super Fine | Fingering, sock (4 ply) | 1–3 (2.25–3.25) | B-1 to E-4 (2.25–3.5) | 27–32 | 14–17 | 365–480 | Socks, shawls, fine garments |
| 2 — Fine | Sport, baby (5 ply) | 3–5 (3.25–3.75) | E-4 to 7 (3.5–4.5) | 23–26 | 12–14 | 280–350 | Colourwork, baby items, light sweaters |
| 3 — Light | DK, light worsted (8 ply) | 5–7 (3.75–4.5) | 7 to I-9 (4.5–5.5) | 21–24 | 11–13 | 220–260 | Sweaters, accessories, kids' garments |
| 4 — Medium | Worsted, Aran (10 ply) | 7–9 (4.5–5.5) | I-9 to K-10½ (5.5–6.5) | 16–20 | 9–11 | 180–220 | Almost anything — the all-rounder |
| 5 — Bulky | Bulky, chunky (12 ply) | 9–11 (5.5–8) | K-10½ to M-13 (6.5–9) | 12–15 | 7–9 | 100–140 | Cosy sweaters, throws, rugs |
| 6 — Super Bulky | Super bulky (14 ply) | 11–17 (8–12.75) | M-13 to Q (9–15) | 7–11 | 5–6 | 50–100 | Cowls, scarves, hats |
| 7 — Jumbo | Jumbo | 17+ (15+) | Q and larger (15+) | ≤6 | 1–4 | <50 | Arm knitting, big-stitch blankets |
*WPI and metres per 100 g are approximate — actual figures vary with fibre, spin, and brand. Always knit a gauge swatch.
Yarn Substitution Guidelines
If your pattern calls for a specific yarn but you prefer to use a different yarn, you can use the yarn weights as a basis for substitution. While most yarns within a yarn weight category are interchangeable, not all are identical. It is imperative to construct a gauge swatch with the yarn that you intend to use in a project to be sure that you are matching the gauge of your project pattern. Work through these in order:
- Match the weight category (e.g. swap one DK for another DK).
- Compare length per 100 g — two DKs can differ by 40 m/100 g, which changes how much you need and how the fabric feels.
- Check WPI if the yarn is unlabelled: wrap it snugly around a ruler for one inch, count the strands, and match it to the chart above.
- Consider the fibre — drape, halo, warmth, and stitch definition vary even within a weight.
- Always swatch to confirm you match the pattern's gauge.
For brand-to-brand examples and a substitution checklist, see our complete yarn substitution guide.
Weight 0: Lace Weight
Quick answer: Lace is the finest standard weight (#0), knit on 1.5–2.25 mm needles at roughly 33–40 stitches over 4 inches.
The lightest weight of yarn, producing an extremely fine gauge fabric. Lace weight yarns are often knit or crocheted on larger needles and hooks to create lacy, openwork patterns.
Best Uses: Delicate shawls, wraps, and intricate lacework
Recommended Knitting Needles: US 000–1 (1.5mm–2.25mm)
Recommended Crochet Hooks: Steel hooks 1.6mm–1.4mm or Regular 2.2mm
Common Gauge (over 4 inches):
Knitting Stockinette: 33–40 stitches | Crochet Single Crochet: 32–42 stitches
WPI (approx.): 18+ (cobweb 30+) | Approx. length: 600–1000+ m/100g | Also called: 1–2 ply, light fingering
Note: Gauge is difficult to determine for lace weight yarns as it is often used to make lacy, open stitch work. Always follow the gauge as stated in your pattern.
Weight 1: Super Fine (Fingering or Sock)
Quick answer: Fingering weight (#1, "4-ply") is knit on 2.25–3.25 mm needles at about 27–32 stitches over 4 inches — the classic sock and fine-shawl yarn.
More often referred to as fingering weight yarn, this is a bit heavier than lace and creates a more substantial fabric. Still very fine gauged, fingering weight yarn can also produce lovely openwork projects.
Best Uses: Socks, shawls, baby and adult garments, accessories
Recommended Knitting Needles: US 1–3 (2.25mm–3.25mm)
Recommended Crochet Hooks: B-1 to E-4 (2.25mm–3.5mm)
Common Gauge (over 4 inches):
Knitting Stockinette: 27–32 stitches | Crochet Single Crochet: 21–32 stitches
WPI (approx.): 14–17 | Approx. length: 365–480 m/100g | Also called: 4-ply, sock
Weight 2: Fine Weight (Sport)
Quick answer: Sport weight (#2, "5-ply") sits just above fingering, knit on 3.25–3.75 mm needles at about 23–26 stitches over 4 inches.
Often called sport or baby weight, this yarn is slightly heavier than fingering weight. Sport weight yarns are excellent for colorwork, textured fabric, and cabling.
Best Uses: Cozy socks, sweaters with great ease and drape, baby items
Recommended Knitting Needles: US 3–5 (3.25–3.75mm)
Recommended Crochet Hooks: E-4 to 7 (3.5mm–4.5mm)
Common Gauge (over 4 inches):
Knitting Stockinette: 23–26 stitches | Crochet Single Crochet: 16–20 stitches
WPI (approx.): 12–14 | Approx. length: 280–350 m/100g | Also called: 5-ply, baby
Weight 3: Light Weight (DK / Double Knit)
Quick answer: DK (#3, "8-ply") is a light worsted weight, knit on 3.75–4.5 mm needles at about 21–24 stitches over 4 inches.
More commonly called DK or Double Knit, this yarn creates a lovely, drapey fabric that is popular because it works up much faster than its thinner counterparts.
Best Uses: Sweaters, accessories, children's garments
Recommended Knitting Needles: US 5–7 (3.75mm–4.5mm)
Recommended Crochet Hooks: 7 to I-9 (4.5mm–5.5mm)
Common Gauge (over 4 inches):
Knitting Stockinette: 21–24 stitches | Crochet Single Crochet: 12–17 stitches
WPI (approx.): 11–13 | Approx. length: 220–260 m/100g | Also called: 8-ply, light worsted
Not sure whether to pick DK or worsted? Read DK vs worsted: what's the difference?
Weight 4: Medium Weight (Worsted and Aran)
Quick answer: Worsted (#4, "10-ply") is the workhorse weight, knit on 4.5–5.5 mm needles at about 16–20 stitches over 4 inches. Aran sits at the heavier end of the same category.
More commonly known as worsted weight, this is the workhorse yarn of the knitting and crochet world. This yarn weight is very popular because it can be used for just about anything, bridging the gap between lighter and heavier weight yarns. Perfect for beginners of either craft. Aran vs worsted: Aran is a touch thicker; when substituting between the two, compare length per 100 g rather than the label alone.
Best Uses: Garments, accessories, home décor — virtually anything!
Recommended Knitting Needles: US 7–9 (4.5mm–5.5mm)
Recommended Crochet Hooks: I-9 to K-10½ (5.5mm–6.5mm)
Common Gauge (over 4 inches):
Knitting Stockinette: 16–20 stitches | Crochet Single Crochet: 11–14 stitches
WPI (approx.): 9–11 (Aran 8–10) | Approx. length: 180–220 m/100g (Aran 140–180) | Also called: 10-ply, afghan
Weight 5: Bulky Weight
Quick answer: Bulky (#5, "12-ply", a.k.a. chunky) is roughly twice as thick as worsted, knit on 5.5–8 mm needles at about 12–15 stitches over 4 inches.
Approximately twice as thick as worsted weight yarn. Sometimes referred to as chunky, craft, or rug yarn, it usually works up quickly using larger needles or hooks.
Best Uses: Heavy, cozy sweaters, rugs, throws
Recommended Knitting Needles: US 9–11 (5.5mm–8mm)
Recommended Crochet Hooks: K-10½ to M-13 (6.5mm–9mm)
Common Gauge (over 4 inches):
Knitting Stockinette: 12–15 stitches | Crochet Single Crochet: 8–11 stitches
WPI (approx.): 7–9 | Approx. length: 100–140 m/100g | Also called: 12-ply, chunky, craft, rug
Bulky or super bulky? See bulky vs super bulky: what's the difference?
Weight 6: Super Bulky
Quick answer: Super bulky (#6, "14-ply") is a very thick yarn, knit on 8–12.75 mm needles at about 7–11 stitches over 4 inches.
A very thick yarn that works up quickly on large needles and hooks.
Best Uses: Cowls, scarves, hats
Recommended Knitting Needles: US 11–17 (8mm–12.75mm)
Recommended Crochet Hooks: M-13 to Q (9mm–15mm)
Common Gauge (over 4 inches):
Knitting Stockinette: 7–11 stitches | Crochet Single Crochet: 7–9 stitches
WPI (approx.): 5–6 | Approx. length: 50–100 m/100g | Also called: 14-ply, super chunky, roving
Weight 7: Jumbo
Quick answer: Jumbo (#7) is the thickest standard weight, worked on 15 mm-plus needles (or by arm) at 6 or fewer stitches over 4 inches.
The thickest yarn weight currently available. These super thick yarns are used in big stitch projects or for arm knitting or crochet.
Best Uses: Big stitch cowls, scarves, hats, blankets, arm knitting projects
Recommended Knitting Needles: US 17 and larger (15mm and larger)
Recommended Crochet Hooks: Q and larger (15mm and larger)
Common Gauge (over 4 inches):
Knitting Stockinette: 6 stitches and fewer | Crochet Single Crochet: 6 stitches and fewer
WPI (approx.): 1–4 | Approx. length: <50 m/100g | Also called: roving
Frequently Asked Questions
Is DK the same as worsted?
No. DK (weight 3, "8-ply") is lighter than worsted (weight 4, "10-ply"). DK knits at about 21–24 sts / 4" on 3.75–4.5 mm needles; worsted knits at about 16–20 sts / 4" on 4.5–5.5 mm needles. See DK vs worsted.
What is fingering weight yarn?
Fingering is a super-fine, weight-1 yarn (called "4-ply" in the UK and Australia). It knits at roughly 27–32 sts / 4" on 2.25–3.25 mm needles and is the standard choice for socks and fine shawls.
What's the difference between bulky and super bulky?
Bulky (weight 5) knits at about 12–15 sts / 4" on 5.5–8 mm needles; super bulky (weight 6) is thicker, at about 7–11 sts / 4" on 8–12.75 mm needles. See bulky vs super bulky.
How do I substitute one yarn weight for another?
Match the weight category, then compare metres per 100 g and WPI, factor in the fibre, and knit a gauge swatch to confirm you hit the pattern's gauge.
What does WPI (wraps per inch) mean?
WPI is how many times a yarn wraps snugly around a ruler within one inch. It's the quickest way to identify the weight of an unlabelled yarn — more wraps means a finer yarn.
How do UK "ply" names map to US yarn weights?
Roughly: 2-ply = lace, 4-ply = fingering, 5-ply = sport, 8-ply = DK, 10-ply = worsted/Aran, 12-ply = bulky, 14-ply = super bulky. "Ply" here describes thickness, not the literal number of strands.