Yarn weight is the single thing that decides whether your project turns out the size you planned. It's the thickness of the strand, and the industry sorts it into eight categories, #0 through #7, set by the Craft Yarn Council (CYCA). Get the weight right and the hook size, gauge and skein count fall into place. This guide gives you the full chart, the conversions, and one thing most guides skip: why a yarn's label number can differ from how it actually works up.
Key Takeaways - The CYCA standard sorts yarn into 8 weights, #0 (Lace) to #7 (Jumbo), by gauge (Craft Yarn Council). - Match your pattern by gauge and hook/needle size, not just the number on the label. - Chenille and specialty fibres can carry one catalog label yet work up at a different gauge - so a #6-labelled chenille can behave like a worsted.
What is yarn weight, and why does it matter?
Yarn weight means the thickness of the strand, not how heavy the skein is. It matters because thickness sets your gauge - the number of stitches that fit in 4 inches - and gauge decides the finished size of everything you make. A sweater knit in the wrong weight can come out two sizes off. Our best yarn for sweaters guide picks the right weight for the job.
The Craft Yarn Council created the Standard Yarn Weight System to end the confusion between regional names like worsted, aran, DK and chunky. It runs from #0 (the finest) to #7 (the thickest). Every weight has a typical gauge range and a recommended hook and needle size, so a pattern written for one #4 worsted works with another.
Interest in getting this right is climbing. In 2026, Michaels reported yarn accessory sales up 40% year over year as new makers picked up hooks and needles (Michaels 2026 Creativity Trend Report, March 2026). More beginners means more people meeting the weight system for the first time.
The CYCA yarn weight chart (#0 to #7)
The full Craft Yarn Council system is below. Knit gauge is stitches per 4 inches (10 cm) in stockinette; hook and needle ranges are the recommended starting points. Always swatch to confirm.
| CYCA | Name | Also called | Knit gauge (sts/4in) | Needle | Crochet hook |
|---|---|---|---|---|---|
| 0 | Lace | cobweb, thread, 2-ply | 33-40 | 1.5-2.25mm (US 000-1) | steel 1.6-2.25mm |
| 1 | Super Fine | fingering, sock, baby | 27-32 | 2.25-3.25mm (US 1-3) | 2.25-3.5mm |
| 2 | Fine | sport, baby | 23-26 | 3.25-3.75mm (US 3-5) | 3.5-4.5mm |
| 3 | Light | DK, light worsted | 21-24 | 3.75-4.5mm (US 5-7) | 4.5-5.5mm |
| 4 | Medium | worsted, aran, afghan | 16-20 | 4.5-5.5mm (US 7-9) | 5.5-6.5mm |
| 5 | Bulky | chunky, craft, rug | 12-15 | 5.5-8mm (US 9-11) | 6.5-9mm |
| 6 | Super Bulky | super chunky, roving | 7-11 | 8-12.75mm (US 11-17) | 9-15mm |
| 7 | Jumbo | roving, arm-knitting | 6 or fewer | 12.75mm+ (US 17+) | 15mm+ |
The lower the number, the finer the yarn and the more stitches you pack into 4 inches. Lace and fingering suit shawls and socks; worsted is the all-rounder for sweaters and blankets; bulky and super bulky make fast, cosy projects.
How do I know what weight my yarn is?
Check three things, in order: the label, the gauge, and (if those are missing) the wraps-per-inch test. Most yarn bands print the CYCA number inside a small yarn-skein symbol, plus a recommended gauge and hook size. That symbol is your fastest answer.
If the label is gone, use wraps per inch (WPI). Wrap the strand snugly around a ruler, side by side with no gaps or overlap, count how many wraps fill one inch, then compare:
| Wraps per inch (approx) | Yarn weight |
|---|---|
| ~5-6 | Super Bulky (#6) |
| ~7-8 | Bulky (#5) |
| ~9 | Worsted (#4) |
| ~11 | DK / Light (#3) |
| ~12 | Sport / Fine (#2) |
| ~14 | Super Fine (#1), fingering |
| ~18+ | Lace (#0) |
These WPI figures follow the Ravelry reference (finer yarn = more wraps).
WPI gets you close, but the real test is a gauge swatch. Knit or crochet a 4-inch square on the hook your pattern names, then count stitches. If you're off, change hook size before you change yarn. Two yarns can even share a weight number yet knit a touch differently between brands, so the swatch is always the final word.
Yarn weight conversions: US, UK and Australian terms
The same yarn goes by different names around the world. UK and Australian patterns often use a "ply" number, which describes tradition more than an exact thickness, so treat these as close equivalents and confirm by gauge.
| CYCA (US) | UK / Australia | Common name |
|---|---|---|
| #1 Super Fine | 4-ply | fingering, sock |
| #2 Fine | 5-ply | sport |
| #3 Light | 8-ply | DK |
| #4 Medium | 10-ply | worsted, aran |
| #5 Bulky | 12-ply | chunky |
| #6 Super Bulky | 14-16 ply | super chunky |
So a UK pattern asking for "8-ply" wants a #3 DK; "10-ply" wants a #4 worsted. When a conversion and your gauge swatch disagree, trust the swatch.
Why a yarn's label can differ from its real working gauge
This is the part most charts skip. A weight label describes a yarn's appearance and density, but chenille, mercerized cotton and microfibre can look like one weight and work up like another. For how the fibres themselves differ, see our yarn fiber guide. A plush chenille can look super bulky on the shelf yet crochet at a worsted gauge, because the soft pile adds bulk without adding yards-per-gram density.
We mapped every Estako line's real working gauge against its label this year, and the chenilles surprised us most. That's why we publish two numbers for our own yarn. On every Estako product page you see the catalog weight (the number on the shelf). For hook size and skein math, what matters is the working gauge. When the two disagree, the rule is simple: match your pattern by hook or needle size, not by the label number.
It's not a quirk unique to us. Any chenille or specialty fibre can behave this way. Knowing it saves you from buying a "super bulky" for a worsted pattern and ending up with a stiff, oversized fabric.
Which Estako yarn is which weight?
Every Estako line is OEKO-TEX® Standard 100 certified. Here's the full range with both numbers - the catalog weight you'll see on the page, and the gauge it actually works at, so you can match any pattern.
| Estako line | Catalog weight | Works at | Fibre | Hook / needle | Skein |
|---|---|---|---|---|---|
| Royal Cotton | #1 Super Fine | DK gauge | 100% mercerized Giza cotton | 4mm hook | 50g/137 yds |
| Dream | #1 Super Fine | DK gauge | 100% microfibre acrylic | 2.5-4mm | 100g/383 yds |
| Happy Wool | #1 Super Fine | worsted gauge | 40% merino / 20% cashmere-type polyamide / 40% acrylic | 4.5-5mm | 50g/191 yds |
| Happy Cotton | #2 Sport/Fine | DK gauge | 60% cotton / 40% acrylic | 3-4mm | 50g/180 yds |
| Jeans | #2 Sport/Fine | DK gauge | 55% cotton / 45% acrylic | 2.5-4mm | 50g/174 yds |
| DailyKnit-DK | #3 Light/DK | DK (aligned) | 100% anti-pilling acrylic | 4mm | 100g/273 yds |
| Downy | #3 Light/DK | DK (aligned) | 40% acrylic / 60% polyamide | 3-4mm | 100g/267 yds |
| Star-Worsted | #4 Worsted | worsted (aligned) | 75% acrylic / 25% wool | 4.5-5.5mm | 100g/186 yds |
| Eyelash | #4 Worsted | worsted (novelty) | 100% polyester eyelash | 4-5mm | 100g/153 yds |
| MegaStar | #5 Bulky | bulky (aligned) | 75% acrylic / 25% wool | 7-10mm | 100g/120 yds |
| Softy | #5 Bulky | worsted gauge (chenille) | 100% polyester plush chenille | 4-5mm hook | 100g/98 yds |
| Cozy | #6 Super Bulky | super bulky (aligned) | 80% acrylic / 20% wool | 9-10mm | 100g/65 yds |
| Velvet | #6 Super Bulky | worsted gauge | 100% polyester chenille | 3.5-4mm hook | 100g/132 yds |
| Velvet XL | #6 Super Bulky | bulky gauge | 100% polyester chenille | 5-6mm hook | 100g/55 yds |
| Fur | #6 Super Bulky | bulky (accent) | 100% polyester faux fur | 7-9mm | 100g/71 yds |
Notice the chenilles. Velvet is labelled #6 but works at a worsted gauge on a 3.5-4mm hook. Royal Cotton is labelled #1 but crochets at DK on a 4mm hook. That sturdy mercerized cotton is also our go-to for a crochet market bag. The label tells you what it looks like; the "works at" column tells you how to use it.
You can also browse by weight: Super Fine #1, Sport #2, Light/DK #3, Worsted #4, Bulky #5, and Super Bulky #6.
How do I pick the right weight for my project?
Start from the finished fabric you want, then pick the weight that gets you there fastest without losing drape. Fine weights give detail and drape; heavy weights give speed and warmth. Fine cotton, for instance, is the maker pick for amigurumi. This quick map covers most makes:
| Project | Best weight | Estako pick |
|---|---|---|
| Delicate shawls, light wraps | fine / light DK | Dream |
| Baby blankets, garments, light tops | #2-#3 Sport / DK | Happy Cotton, Downy |
| Granny squares, market bags | DK-gauge cotton | Royal Cotton |
| Everyday sweaters, blankets | #4 Worsted | Star-Worsted, Happy Wool |
| Amigurumi plush | worsted-gauge chenille | Velvet, Velvet XL |
| Quick scarves, beanies | #5 Bulky | MegaStar, Softy |
| Chunky cable cardigans, throws | #6 Super Bulky | Cozy |
For the trend driving a lot of these projects right now, see our Grandmacore yarn guide.
Buying several skeins in one weight for a larger project? Match the dye lots so the color stays consistent from the first row to the last.
Frequently Asked Questions
What are the yarn weights from thinnest to thickest?
The CYCA system runs #0 Lace, #1 Super Fine (fingering), #2 Fine (sport), #3 Light (DK), #4 Medium (worsted), #5 Bulky, #6 Super Bulky, and #7 Jumbo. Number 0 is the finest and 7 the thickest (Craft Yarn Council).
Is DK the same as worsted?
No. DK is #3 Light and worsted is #4 Medium, so worsted is a step thicker. DK knits at about 21-24 stitches per 4 inches on a 3.75-4.5mm needle; worsted knits at 16-20 stitches on a 4.5-5.5mm needle. UK patterns call DK "8-ply" and worsted "10-ply".
What does "4-ply" mean in a UK or Australian pattern?
UK and Australian "4-ply" is roughly a #1 Super Fine (fingering) in the US system. The ply number is a traditional label, not an exact thickness, so confirm with a gauge swatch. 8-ply is DK (#3) and 10-ply is worsted (#4).
How do I measure yarn weight without a label?
Use wraps per inch (WPI): wrap the strand snugly around a ruler with no gaps, count the wraps in one inch, and compare. Roughly 9 wraps is worsted, 11 is DK, 14 is fingering, and 5-6 is super bulky. Then knit a gauge swatch to confirm before starting.
Why does my yarn say #6 but crochet like a worsted?
Chenille and specialty fibres can carry a catalog label based on their plush appearance while working up at a finer gauge. Estako Velvet is labelled #6 Super Bulky but works at worsted gauge with a 3.5-4mm hook. Always match your pattern by hook or needle size, not the label number.
What yarn weight is best for beginners?
A #4 Medium (worsted) is the most forgiving starting weight: stitches are easy to see, it works on a 4.5-5.5mm hook or needle, and most beginner patterns use it. Estako Star-Worsted is a smooth, washable worsted that's well suited to first projects.
Find your weight and cast on
Bookmark the chart, match your pattern by gauge and hook size, and swatch before you commit a whole project. When you're ready, browse the full 16-yarn curated collection - every line is OEKO-TEX® Standard 100 certified, with both the catalog weight and the real working gauge on each page.
Happy making. - Esref & the Estako team
Sources
- Craft Yarn Council, "Standard Yarn Weight System," retrieved 2026-06-01 - https://www.craftyarncouncil.com/standards/yarn-weight-system
- Ravelry, "Yarn Weight" reference (WPI + ply conversions), retrieved 2026-06-01 - https://www.ravelry.com/help/yarn/weights
- Michaels Companies, "Michaels Unveils 2026 Creativity Trend Report," PR Newswire, March 10 2026 - retrieved 2026-06-01 - https://www.prnewswire.com/news-releases/michaels-unveils-2026-creativity-trend-report-revealing-a-shift-towards-creative-living-in-the-analog-era-302709301.html
