Knitting with thick yarn is love at first stitch: projects grow before your eyes, the texture is wonderfully bold, and you can finish a sweater or beanie in a single weekend. But beginners and experienced knitters alike ask the same question: what size needles do you need for chunky yarn?
Your needles decide everything: whether a sweater drapes softly or ends up stiff as a board, and whether a throw blanket turns out airy or far too heavy. In this guide we use two yarns from The Woolcatcher to show how to choose, and why "the thicker the needle, the better" doesn't always hold.
Short answer: for super bulky yarn, use US 17–19 (12–15 mm) needles for garments and US 36–50 (20–25 mm) for blankets; for chunky/bulky yarn, use US 10–11 (6–8 mm).
Super Bulky Yarn: Which Needle Size?
This category covers yarn with around 109 yd per 7 oz (100 m per 200 g). It's the yarn behind those big, highly textured stitches you see all over Instagram and Pinterest.
Our example: FACES yarn (7 oz / 109 yd, 100% Peruvian wool). The label recommends US 15–50 (10–25 mm) needles, because the right size depends on the project:
- Sweaters, cardigans and beanies: US 17–19 (12–15 mm) needles. This gives a dense yet pliable fabric: wind won't blow through your beanie, and a cardigan keeps its shape instead of stretching under its own weight.
- Throw blankets: US 36–50 (20–25 mm) needles. A blanket needs lightness and drape; knitted on US 19 (15 mm) needles it would be too stiff and heavy.
- Scarves and cowls: US 17–19 (12–15 mm). The fabric is warm, squishy and cozy enough for deep winter.
Chunky / Bulky Yarn: Which Needle Size?
The more classic thick yarn: finer than super bulky, but still quick to knit, with bold stitch definition.
Our example: BeMe yarn (3.5 oz / 131 yd), the workhorse of our range.
- Sweaters and most wardrobe staples: US 10–11 (6–8 mm) needles (the label recommends US 10½–11 / 6.5–8 mm). It's the sweet spot: an even, moderately dense, hard-wearing fabric that stays soft to the touch.
Knitting Needle Size Chart: mm to US and UK
Patterns from international designers often use US or old UK needle sizes. Save this chart for thick yarns:
| Metric | US | UK |
|---|---|---|
| 6 mm | 10 | 4 |
| 6.5 mm | 10½ | 3 |
| 8 mm | 11 | 0 |
| 9 mm | 13 | 00 |
| 10 mm | 15 | 000 |
| 12 mm | 17 | — |
| 15 mm | 19 | — |
| 19 mm | 35 | — |
| 20 mm | 36 | — |
| 25 mm | 50 | — |
Why Gauge Matters: Knit a Swatch First
Even if the yarn label lists a needle size, your personal tension can change everything. Some knitters work tightly, others loosely.
If you tend to pull the yarn tight (very common when casting on with chunky yarn), go up a needle size or two. If your fabric looks loose or gappy, go down a size. Always knit a 4 × 4 in (10 × 10 cm) swatch before starting a garment.
Wood or Metal: Which Needles Are Best for Thick Yarn?
Size isn't everything: the material of your needles matters too.
- Wooden needles (bamboo, beech, birch): the best choice for beginners and slippery yarns such as high-alpaca blends. Wood grips the yarn slightly, so heavy stitches don't slide off by accident. Large wooden needles are also much lighter than metal ones, which means less wrist strain.
- Metal needles: for experienced knitters. They're slicker, so stitches glide faster. With classic sheep's wool, which has a natural grip, metal helps you speed up.
All our circular knitting needles are made of beech wood, in US 10, 11, 15, 17 and 19 (6, 8, 10, 12 and 15 mm): exactly the sizes in this guide.
New to knitting? On our Learn to knit page we have already picked the needles for you: 3 beginner projects with FACES yarn, US 15 and 17 (10 and 12 mm) needles, a free pattern and videos.
Not sure what weight your yarn is? See our yarn weight chart, and for how many skeins you need, the super bulky yarn guide.
Choosing needles isn't strict math; it's part of the creative process. Experiment with sizes until you find the perfect texture for your next cozy project!
