Knitting Needle Size Chart

For worsted weight (size 4 — Medium), the standard starting range is 4.5 mm to 5.5 mm (US 7 to 9). Most patterns call for a 5.0 mm or 5.5 mm needle. Always check your pattern gauge swatch — needle size affects stitch tension more than yarn weight alone.

US needle sizes are informal labels, not precise measurements. Different manufacturers settled on slightly different mm diameters for the same number. The CYC standard table itself shows this: both 3.125 mm and 3.25 mm are listed as US size 3; both 4.0 mm and 4.25 mm as US size 6; both 5.25 mm and 5.5 mm as US size 9. The mm measurement stamped on the needle is the only reliable number.

The old UK/Canadian numbering system is largely obsolete — most modern UK patterns now specify metric millimetres. The old system ran inversely (higher numbers were smaller needles) and varied by manufacturer. The Craft Yarn Council standard, which this table follows, does not include old UK sizes. If you have an old UK pattern, a general conversion guide: UK 14 ≈ 2 mm, UK 10 ≈ 3.25 mm, UK 8 ≈ 4 mm, UK 6 ≈ 5 mm, UK 0 ≈ 8 mm.

Single point needles (straight, one pointed tip) are used for flat knitting worked in rows. Double point needles (DPNs) have tips at both ends and work in sets of 4–5 for small-circumference knitting in the round — socks, sleeves, hat crowns. Circular needles connect two tips with a cable and knit both flat and in the round; their length should be shorter than the circumference of your project for seamless knitting.

Yes. Metal needles are slippery and fast — good for experienced knitters and slick yarns like silk. Bamboo and wood have more grip, which slows stitches from sliding off accidentally — recommended for beginners, loose knitters, and slippery cast-ons. Acrylic plastic sits in the middle. Needle material does not change the gauge, but it changes the feel of knitting significantly.