US 8 Knitting Needle Size
US 8 is probably the single most-used needle size in knitting. Here's what it measures in every system and what to knit with it.
5.0 mm · UK 6 · Japanese ~10号 · Yarn: Worsted (#4)
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US 8 in Every Sizing System
| System | Size | Notes |
|---|---|---|
| Metric | 5.0 mm | Exact — marked on most modern needles |
| US | 8 | American standard |
| UK / Australian | 6 | Note: UK 8 ≠ US 8 (they run opposite directions) |
| Japanese | ~10号 | 10号 = 5.1mm — close but not exact |
| Yarn weight | Worsted (#4) | Standard gauge: 18–20 sts per 4" |
What Makes US 8 So Common
Worsted weight is the most widely available yarn weight in the US, and US 8 is the needle most worsted patterns call for. Walk into any yarn shop, and the majority of the patterns on display will say "US 8" somewhere on the front. It's the middle of the road in the best possible way — not so small that it strains your eyes, not so big that the fabric feels stiff.
It's also the needle most beginners buy first. Worsted on a size 8 gives you stitches you can actually see, which makes it much easier to spot mistakes and learn to fix them.
The UK size 8 problem
Worth flagging because it catches a lot of people out: UK size 8 is not the same as US size 8. UK 8 is 4.0mm — that's a US 6. The two systems run in completely opposite directions. If you're following a British or Australian pattern, always check the mm measurement rather than going by the number alone.
Japanese patterns
Japanese patterns will call for 10号 (10-gō) when they want something close to 5.0mm. Technically 10号 is 5.1mm, so there's a tiny 0.1mm gap — in practice it makes no difference, but if you're being exact, note it.
What to Knit with US 8 Needles
The short answer: almost anything made with worsted yarn. A few good starting points:
Hats — a classic worsted hat on US 8 circulars works up in a few hours. Good for learning in the round.
Scarves and cowls — beginner-friendly, no shaping, and worsted gives you a warm, drapey fabric.
Sweaters — the majority of published adult sweater patterns use worsted on US 7–9. US 8 sits right in the middle.
Blankets — a US 8 blanket will take a while (a lot of stitches), but the fabric has a nice drape. If you want speed, go up to US 10 or 11.
Dishcloths — not glamorous, but genuinely useful for practicing stitch patterns. Cotton worsted on US 8 knits up quickly.
What it's not suited for
Fine lace (you'd want US 2–4 for that), very chunky blankets (US 11 and up), or sock knitting (US 1–2). A US 8 is too big for sock yarn and too small for super bulky.
Needle Types Available in US 8
Straight needles — the traditional pair. Fine for flat knitting like scarves or blanket squares. Harder to use for large projects where the weight of the work needs support.
Circular needles — the most versatile option. You can knit flat or in the round on the same needle. Most people who knit hats, sweaters, or anything round use circulars. 16" and 24" lengths are the most useful for US 8 projects.
Double-pointed needles (DPNs) — used for small circumference work like mittens, socks (not at US 8 though), and the tops of hats. A set of 5 DPNs in US 8 covers you for mitten thumbs and hat crowns.
Interchangeable tips — if you're building a needle collection, a US 8 tip is one of the first to reach for. Brands like Knitter's Pride, Addi, and ChiaoGoo all make solid US 8 interchangeable sets.
Gauge with US 8 Needles
Standard gauge for worsted on US 8 is roughly 18–20 stitches per 4 inches (10cm). That said, gauge varies a lot depending on the yarn, your tension, and the needle material. Bamboo needles produce slightly tighter fabric than metal; loosely spun wool knits up bigger than tightly plied acrylic.
If your pattern specifies a gauge, always swatch. Knit a square at least 6" across, wash and block it the way you'd treat the finished item, then measure. If your stitch count is too high (stitches are too small), go up a needle size. Too low, go down.