Yarn weight is thickness, not how heavy the ball is. It is the single decision that has the biggest effect on how your finished piece looks, drapes, wears and how long it takes — more than fiber, and far more than brand. This page is a comparison, not a ranking: every weight is the right answer to something and the wrong answer to something else.
Need the hook that goes with a weight? The hook size converter maps weights to hooks in every sizing system. Working out how much of it to buy? That is the yarn calculator.
Which weight for my project?
Your yarn
—
- —usual hook
- —UK / AU ply
- —gauge per 4 in
- —yards per 100 g
The eight weights, side by side
Numbers, names and gauge ranges follow the Craft Yarn Council Standard Yarn Weight System. Crochet gauge is single crochet over 4 inches, except lace which is measured in double crochet. Yardage per 100 g is typical, not a standard.
| Weight | Also called | UK / AU ply | Hook | Gauge / 4″ | Yd / 100 g | Good at | Bad at |
|---|---|---|---|---|---|---|---|
| 0Lace | Lace, cobweb, thread, 10-count | 1–2 ply | 1.6–2.25 mm | 32–42 dc | 400–800 yd | Doilies, snowflakes, thread edgings, heirloom and wedding pieces, anything you want to block stiff and see through | Speed of any kind, hiding uneven tension, comfort for hands and eyes over long sessions |
| 1Super fine | Fingering, sock, baby, 4 ply | 3–4 ply | 2.25–3.5 mm | 21–32 sc | 350–450 yd | Socks, shawls with real drape, baby garments, fine colorwork, small detailed amigurumi features | Blankets (months of work), first projects — it splits and shows every wobble |
| 2Fine | Sport, baby | 5 ply | 3.5–4.5 mm | 16–20 sc | 280–350 yd | Baby clothes, lightweight tops, summer garments, amigurumi that needs crisp detail | Fast projects, and finding it easily — big-box stores rarely stock much of it |
| 3Light | DK, light worsted | 8 ply | 4.5–5.5 mm | 12–17 sc | 220–260 yd | Garments that need to hang rather than stand, baby blankets, hats worn under hoods, market bags that keep their shape | One-layer winter warmth, and matching US patterns — most of which assume worsted |
| 4Medium | Worsted, afghan, aran | 10 ply | 5.5–6.5 mm | 11–14 sc | 180–220 yd | Nearly everything: blankets, beanies, amigurumi, bags, dishcloths. Widest color range, cheapest per yard, the weight most free patterns are written in | Fine lace, and close-fitting garments where it can read as bulky and stiff on the body |
| 5Bulky | Chunky, craft, rug | 12 ply | 6.5–9 mm | 8–11 sc | 100–140 yd | Blankets you want finished this month, chunky beanies and scarves, baskets that stand up, rugs | Detail of any kind, amigurumi (stuffing shows through), fitted garments — and your budget, because it needs more balls than you expect |
| 6Super bulky | Super chunky, roving | 14–16 ply | 9–15 mm | 7–9 sc | 55–90 yd | A blanket in a weekend, big soft scarves, pet beds, floor cushions | Drape, anything worn close to the body, and stitch definition — texture patterns disappear |
| 7Jumbo | Jumbo, roving, arm-knit | — | 15 mm and larger | 6 sc and fewer | 20–50 yd | Statement throws, giant baskets, floor poufs — pieces where the scale is the point | Wearables, hooks are unwieldy, the fabric is heavy, and a ball goes almost nowhere |
Substituting one weight for another
| If the pattern says | And you have | What to do |
|---|---|---|
| Worsted (4) | DK (3) | Go up one hook size, or add stitches to hit the pattern's finished width. Fine for blankets and scarves; swatch first for anything fitted. |
| Worsted (4) | Bulky (5) | Go down one hook size and expect a bigger, stiffer piece. Recalculate the stitch count from the finished measurement, not the pattern's number. |
| DK (3) | Fingering (1) | Hold two strands together. Two strands of fingering behave close to sport or DK. |
| Bulky (5) | DK (3) | Hold two strands together — two DK strands land near aran or bulky. |
| Super bulky (6) | Worsted (4) | Hold two or three strands together. Two worsted strands are roughly bulky, three roughly super bulky. |
| Any weight | Same weight, different fiber | Swatch. Cotton has no bounce and grows under its own weight; wool blocks and springs back; acrylic keeps whatever shape you gave it. |
Holding strands together changes the yardage as well as the thickness — two strands means twice the yards. Run the total through the yarn calculator at the resulting weight before you buy.
How to read a ball band
The number in the little skein symbol is the weight, 0 through 7. Next to it you will usually find a recommended hook size and a gauge, both of which are the manufacturer's starting suggestion rather than an instruction — your pattern's gauge always wins. The other two numbers that matter are the weight in grams and the length in yards or meters, and it is the length you buy by. Two 100 g balls of the same weight class can differ by 80 yards depending on fiber, which is why substituting by ball count rather than yardage is how people run out.
If the band is long gone, use wraps per inch: wrap the yarn snugly but unstretched around a ruler for one inch and count. Roughly 9 wraps is bulky, 11 to 12 is worsted, 13 to 14 is DK, 15 to 18 is sport or fingering, and above 18 you are into lace.
A worked example
Say you want to make a 50 × 60 inch throw and you are deciding between worsted and bulky, because bulky “works up faster”.
- Worsted: about 2,264 yards in double crochet. At roughly 200 yd per 100 g ball that is 12 balls.
- Bulky: about 1,721 yards — fewer yards, because thicker yarn covers more area per yard. But a bulky ball holds only about 120 yd, so that is 15 balls.
- The bulky throw is faster to crochet and usually more expensive to buy, and it will be noticeably stiffer and heavier on a lap.
Neither is wrong. That is the whole point of a decision table rather than a ranking: “faster” and “cheaper” are not the same axis, and the yarn that is right for a lap blanket for a grandparent is not the one that is right for a baby gift.
Fiber changes the answer too
Weight decides thickness; fiber decides behaviour. Cotton has almost no stretch, holds a crisp stitch and grows under its own weight, which makes it excellent for wash cloths, baskets and market bags and difficult for a fitted hat. Wool springs back, blocks beautifully and forgives uneven tension, which is why garment patterns assume it. Acrylic is durable, washable, cheap and endlessly available, keeps whatever shape you give it, and cannot be blocked into a different one — the reason it dominates blankets and machine-washable baby items. A worsted cotton and a worsted wool are the same weight and will not behave the same at all.
Questions people ask
What are the yarn weights in order?
0 lace, 1 super fine (fingering, sock), 2 fine (sport), 3 light (DK), 4 medium (worsted, aran), 5 bulky (chunky), 6 super bulky, 7 jumbo. In the UK and Australia the same yarns are named by ply: 4 ply is super fine, 8 ply is DK, 10 ply is worsted, 12 ply is bulky.
What yarn weight is best for beginners?
Medium (4) — worsted, or 10 ply. Thick enough to see your stitches, thin enough that mistakes undo easily, and the weight almost every free pattern is written for. Choose a smooth, light-colored yarn rather than anything fluffy or dark; that matters far more than the brand.
Can I substitute DK for worsted yarn?
Usually, with adjustments. DK is one step lighter, so at the same hook you get a looser, drapier, smaller piece. Go up a hook size, or add stitches to hit the finished measurement, and swatch first. Safe for blankets and scarves; not safe for a fitted garment.
How do I know what weight my yarn is without a label?
Wraps per inch: about 9 is bulky, 11–12 worsted, 13–14 DK, 15–18 sport or fingering, above 18 lace. Then swatch and check against the gauge column above.
What happens if I use the wrong weight yarn for a pattern?
The finished size changes and so does the fabric. Lighter than the pattern gives a smaller, floppier piece; heavier gives a bigger, stiffer one. On a blanket or scarf you just add or remove rows. On anything fitted it is the difference between a piece that works and one that does not, which is why patterns quote a gauge rather than a brand.